PaperMC/paper-server/patches/sources/net/minecraft/world/entity/Entity.java.patch

--- a/net/minecraft/world/entity/Entity.java
+++ b/net/minecraft/world/entity/Entity.java
@@ -59,6 +59,8 @@
 import net.minecraft.network.protocol.Packet;
 import net.minecraft.network.protocol.game.ClientGamePacketListener;
 import net.minecraft.network.protocol.game.ClientboundAddEntityPacket;
+import net.minecraft.network.protocol.game.ClientboundSetEntityDataPacket;
+import net.minecraft.network.protocol.game.ClientboundSetEntityLinkPacket;
 import net.minecraft.network.protocol.game.ClientboundTeleportEntityPacket;
 import net.minecraft.network.protocol.game.VecDeltaCodec;
 import net.minecraft.network.syncher.EntityDataAccessor;
@@ -101,8 +103,6 @@
 import net.minecraft.world.level.ChunkPos;
 import net.minecraft.world.level.ClipContext;
 import net.minecraft.world.level.Explosion;
-import net.minecraft.world.level.ItemLike;
-import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.FenceGateBlock;
@@ -138,8 +138,152 @@
 import net.minecraft.world.scores.ScoreHolder;
 import net.minecraft.world.scores.Team;
 import org.slf4j.Logger;
+import net.minecraft.world.level.GameRules;
+import net.minecraft.world.level.ItemLike;
+import net.minecraft.world.level.Level;
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.Server;
+import org.bukkit.block.BlockFace;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Hanging;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.entity.Vehicle;
+import org.bukkit.event.entity.EntityCombustByEntityEvent;
+import org.bukkit.event.hanging.HangingBreakByEntityEvent;
+import org.bukkit.event.vehicle.VehicleBlockCollisionEvent;
+import org.bukkit.event.vehicle.VehicleEnterEvent;
+import org.bukkit.event.vehicle.VehicleExitEvent;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.bukkit.craftbukkit.entity.CraftEntity;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.craftbukkit.event.CraftPortalEvent;
+import org.bukkit.craftbukkit.util.CraftLocation;
+import org.bukkit.entity.Pose;
+import org.bukkit.event.entity.EntityAirChangeEvent;
+import org.bukkit.event.entity.EntityCombustEvent;
+import org.bukkit.event.entity.EntityDismountEvent;
+import org.bukkit.event.entity.EntityDropItemEvent;
+import org.bukkit.event.entity.EntityMountEvent;
+import org.bukkit.event.entity.EntityPortalEvent;
+import org.bukkit.event.entity.EntityPoseChangeEvent;
+import org.bukkit.event.entity.EntityRemoveEvent;
+import org.bukkit.event.entity.EntityTeleportEvent;
+import org.bukkit.event.entity.EntityUnleashEvent;
+import org.bukkit.event.entity.EntityUnleashEvent.UnleashReason;
+import org.bukkit.event.player.PlayerTeleportEvent;
+import org.bukkit.plugin.PluginManager;
+// CraftBukkit end
 
 public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess, ScoreHolder {
+
+    // CraftBukkit start
+    private static final int CURRENT_LEVEL = 2;
+    public boolean preserveMotion = true; // Paper - Fix Entity Teleportation and cancel velocity if teleported; keep initial motion on first setPositionRotation
+    static boolean isLevelAtLeast(CompoundTag tag, int level) {
+        return tag.contains("Bukkit.updateLevel") && tag.getInt("Bukkit.updateLevel") >= level;
+    }
+
+    // Paper start - Share random for entities to make them more random
+    public static RandomSource SHARED_RANDOM = new RandomRandomSource();
+    private static final class RandomRandomSource extends java.util.Random implements net.minecraft.world.level.levelgen.BitRandomSource {
+        private boolean locked = false;
+
+        @Override
+        public synchronized void setSeed(long seed) {
+            if (locked) {
+                LOGGER.error("Ignoring setSeed on Entity.SHARED_RANDOM", new Throwable());
+            } else {
+                super.setSeed(seed);
+                locked = true;
+            }
+        }
+
+        @Override
+        public RandomSource fork() {
+            return new net.minecraft.world.level.levelgen.LegacyRandomSource(this.nextLong());
+        }
+
+        @Override
+        public net.minecraft.world.level.levelgen.PositionalRandomFactory forkPositional() {
+            return new net.minecraft.world.level.levelgen.LegacyRandomSource.LegacyPositionalRandomFactory(this.nextLong());
+        }
+
+        // these below are added to fix reobf issues that I don't wanna deal with right now
+        @Override
+        public int next(int bits) {
+            return super.next(bits);
+        }
+
+        @Override
+        public int nextInt(int origin, int bound) {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextInt(origin, bound);
+        }
+
+        @Override
+        public long nextLong() {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextLong();
+        }
+
+        @Override
+        public int nextInt() {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextInt();
+        }
+
+        @Override
+        public int nextInt(int bound) {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextInt(bound);
+        }
+
+        @Override
+        public boolean nextBoolean() {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextBoolean();
+        }
+
+        @Override
+        public float nextFloat() {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextFloat();
+        }
+
+        @Override
+        public double nextDouble() {
+            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextDouble();
+        }
+
+        @Override
+        public double nextGaussian() {
+            return super.nextGaussian();
+        }
+    }
+    // Paper end - Share random for entities to make them more random
+    public org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason spawnReason; // Paper - Entity#getEntitySpawnReason
+
+    private CraftEntity bukkitEntity;
+
+    public CraftEntity getBukkitEntity() {
+        if (this.bukkitEntity == null) {
+            // Paper start - Folia schedulers
+            synchronized (this) {
+                if (this.bukkitEntity == null) {
+                    return this.bukkitEntity = CraftEntity.getEntity(this.level.getCraftServer(), this);
+                }
+            }
+            // Paper end - Folia schedulers
+        }
+        return this.bukkitEntity;
+    }
+    // Paper start
+    public CraftEntity getBukkitEntityRaw() {
+        return this.bukkitEntity;
+    }
+    // Paper end
+
+    // CraftBukkit - SPIGOT-6907: re-implement LivingEntity#setMaximumAir()
+    public int getDefaultMaxAirSupply() {
+        return Entity.TOTAL_AIR_SUPPLY;
+    }
+    // CraftBukkit end
 
     private static final Logger LOGGER = LogUtils.getLogger();
     public static final String ID_TAG = "id";
@@ -224,7 +368,7 @@
     private static final EntityDataAccessor<Boolean> DATA_CUSTOM_NAME_VISIBLE = SynchedEntityData.defineId(Entity.class, EntityDataSerializers.BOOLEAN);
     private static final EntityDataAccessor<Boolean> DATA_SILENT = SynchedEntityData.defineId(Entity.class, EntityDataSerializers.BOOLEAN);
     private static final EntityDataAccessor<Boolean> DATA_NO_GRAVITY = SynchedEntityData.defineId(Entity.class, EntityDataSerializers.BOOLEAN);
-    protected static final EntityDataAccessor<Pose> DATA_POSE = SynchedEntityData.defineId(Entity.class, EntityDataSerializers.POSE);
+    protected static final EntityDataAccessor<net.minecraft.world.entity.Pose> DATA_POSE = SynchedEntityData.defineId(Entity.class, EntityDataSerializers.POSE);
     private static final EntityDataAccessor<Integer> DATA_TICKS_FROZEN = SynchedEntityData.defineId(Entity.class, EntityDataSerializers.INT);
     private EntityInLevelCallback levelCallback;
     private final VecDeltaCodec packetPositionCodec;
@@ -253,7 +397,68 @@
     private final List<Entity.Movement> movementThisTick;
     private final Set<BlockState> blocksInside;
     private final LongSet visitedBlocks;
+    // CraftBukkit start
+    public boolean forceDrops;
+    public boolean persist = true;
+    public boolean visibleByDefault = true;
+    public boolean valid;
+    public boolean inWorld = false;
+    public boolean generation;
+    public int maxAirTicks = this.getDefaultMaxAirSupply(); // CraftBukkit - SPIGOT-6907: re-implement LivingEntity#setMaximumAir()
+    @Nullable // Paper - Refresh ProjectileSource for projectiles
+    public org.bukkit.projectiles.ProjectileSource projectileSource; // For projectiles only
+    public boolean lastDamageCancelled; // SPIGOT-5339, SPIGOT-6252, SPIGOT-6777: Keep track if the event was canceled
+    public boolean persistentInvisibility = false;
+    public BlockPos lastLavaContact;
+    // Marks an entity, that it was removed by a plugin via Entity#remove
+    // Main use case currently is for SPIGOT-7487, preventing dropping of leash when leash is removed
+    public boolean pluginRemoved = false;
+    // Spigot start
+    public final org.spigotmc.ActivationRange.ActivationType activationType = org.spigotmc.ActivationRange.initializeEntityActivationType(this);
+    public final boolean defaultActivationState;
+    public long activatedTick = Integer.MIN_VALUE;
+    public void inactiveTick() { }
+    // Spigot end
+    protected int numCollisions = 0; // Paper - Cap entity collisions
+    public boolean fromNetherPortal; // Paper - Add option to nerf pigmen from nether portals
+    public boolean spawnedViaMobSpawner; // Paper - Yes this name is similar to above, upstream took the better one
+    // Paper start - Entity origin API
+    @javax.annotation.Nullable
+    private org.bukkit.util.Vector origin;
+    @javax.annotation.Nullable
+    private UUID originWorld;
+    public boolean freezeLocked = false; // Paper - Freeze Tick Lock API
+    public boolean fixedPose = false; // Paper - Expand Pose API
 
+    public void setOrigin(@javax.annotation.Nonnull Location location) {
+        this.origin = location.toVector();
+        this.originWorld = location.getWorld().getUID();
+    }
+
+    @javax.annotation.Nullable
+    public org.bukkit.util.Vector getOriginVector() {
+        return this.origin != null ? this.origin.clone() : null;
+    }
+
+    @javax.annotation.Nullable
+    public UUID getOriginWorld() {
+        return this.originWorld;
+    }
+    // Paper end - Entity origin API
+    public float getBukkitYaw() {
+        return this.yRot;
+    }
+
+    public boolean isChunkLoaded() {
+        return this.level.hasChunk((int) Math.floor(this.getX()) >> 4, (int) Math.floor(this.getZ()) >> 4);
+    }
+    // CraftBukkit end
+    // Paper start
+    public final AABB getBoundingBoxAt(double x, double y, double z) {
+        return this.dimensions.makeBoundingBox(x, y, z);
+    }
+    // Paper end
+
     public Entity(EntityType<?> type, Level world) {
         this.id = Entity.ENTITY_COUNTER.incrementAndGet();
         this.passengers = ImmutableList.of();
@@ -261,7 +466,7 @@
         this.bb = Entity.INITIAL_AABB;
         this.stuckSpeedMultiplier = Vec3.ZERO;
         this.nextStep = 1.0F;
-        this.random = RandomSource.create();
+        this.random = SHARED_RANDOM; // Paper - Share random for entities to make them more random
         this.remainingFireTicks = -this.getFireImmuneTicks();
         this.fluidHeight = new Object2DoubleArrayMap(2);
         this.fluidOnEyes = new HashSet();
@@ -284,6 +489,13 @@
         this.position = Vec3.ZERO;
         this.blockPosition = BlockPos.ZERO;
         this.chunkPosition = ChunkPos.ZERO;
+        // Spigot start
+        if (world != null) {
+            this.defaultActivationState = org.spigotmc.ActivationRange.initializeEntityActivationState(this, world.spigotConfig);
+        } else {
+            this.defaultActivationState = false;
+        }
+        // Spigot end
         SynchedEntityData.Builder datawatcher_a = new SynchedEntityData.Builder(this);
 
         datawatcher_a.define(Entity.DATA_SHARED_FLAGS_ID, (byte) 0);
@@ -292,7 +504,7 @@
         datawatcher_a.define(Entity.DATA_CUSTOM_NAME, Optional.empty());
         datawatcher_a.define(Entity.DATA_SILENT, false);
         datawatcher_a.define(Entity.DATA_NO_GRAVITY, false);
-        datawatcher_a.define(Entity.DATA_POSE, Pose.STANDING);
+        datawatcher_a.define(Entity.DATA_POSE, net.minecraft.world.entity.Pose.STANDING);
         datawatcher_a.define(Entity.DATA_TICKS_FROZEN, 0);
         this.defineSynchedData(datawatcher_a);
         this.entityData = datawatcher_a.build();
@@ -362,20 +574,36 @@
     }
 
     public void kill(ServerLevel world) {
-        this.remove(Entity.RemovalReason.KILLED);
+        this.remove(Entity.RemovalReason.KILLED, EntityRemoveEvent.Cause.DEATH); // CraftBukkit - add Bukkit remove cause
         this.gameEvent(GameEvent.ENTITY_DIE);
     }
 
     public final void discard() {
-        this.remove(Entity.RemovalReason.DISCARDED);
+        // CraftBukkit start - add Bukkit remove cause
+        this.discard(null);
     }
 
+    public final void discard(EntityRemoveEvent.Cause cause) {
+        this.remove(Entity.RemovalReason.DISCARDED, cause);
+        // CraftBukkit end
+    }
+
     protected abstract void defineSynchedData(SynchedEntityData.Builder builder);
 
     public SynchedEntityData getEntityData() {
         return this.entityData;
     }
 
+    // CraftBukkit start
+    public void refreshEntityData(ServerPlayer to) {
+        List<SynchedEntityData.DataValue<?>> list = this.getEntityData().getNonDefaultValues();
+
+        if (list != null) {
+            to.connection.send(new ClientboundSetEntityDataPacket(this.getId(), list));
+        }
+    }
+    // CraftBukkit end
+
     public boolean equals(Object object) {
         return object instanceof Entity ? ((Entity) object).id == this.id : false;
     }
@@ -385,22 +613,35 @@
     }
 
     public void remove(Entity.RemovalReason reason) {
-        this.setRemoved(reason);
+        // CraftBukkit start - add Bukkit remove cause
+        this.setRemoved(reason, null);
     }
 
+    public void remove(Entity.RemovalReason entity_removalreason, EntityRemoveEvent.Cause cause) {
+        this.setRemoved(entity_removalreason, cause);
+        // CraftBukkit end
+    }
+
     public void onClientRemoval() {}
 
     public void onRemoval(Entity.RemovalReason reason) {}
 
-    public void setPose(Pose pose) {
+    public void setPose(net.minecraft.world.entity.Pose pose) {
+        if (this.fixedPose) return; // Paper - Expand Pose API
+        // CraftBukkit start
+        if (pose == this.getPose()) {
+            return;
+        }
+        this.level.getCraftServer().getPluginManager().callEvent(new EntityPoseChangeEvent(this.getBukkitEntity(), Pose.values()[pose.ordinal()]));
+        // CraftBukkit end
         this.entityData.set(Entity.DATA_POSE, pose);
     }
 
-    public Pose getPose() {
-        return (Pose) this.entityData.get(Entity.DATA_POSE);
+    public net.minecraft.world.entity.Pose getPose() {
+        return (net.minecraft.world.entity.Pose) this.entityData.get(Entity.DATA_POSE);
     }
 
-    public boolean hasPose(Pose pose) {
+    public boolean hasPose(net.minecraft.world.entity.Pose pose) {
         return this.getPose() == pose;
     }
 
@@ -417,6 +658,33 @@
     }
 
     public void setRot(float yaw, float pitch) {
+        // CraftBukkit start - yaw was sometimes set to NaN, so we need to set it back to 0
+        if (Float.isNaN(yaw)) {
+            yaw = 0;
+        }
+
+        if (yaw == Float.POSITIVE_INFINITY || yaw == Float.NEGATIVE_INFINITY) {
+            if (this instanceof ServerPlayer) {
+                this.level.getCraftServer().getLogger().warning(this.getScoreboardName() + " was caught trying to crash the server with an invalid yaw");
+                ((CraftPlayer) this.getBukkitEntity()).kickPlayer("Infinite yaw (Hacking?)");
+            }
+            yaw = 0;
+        }
+
+        // pitch was sometimes set to NaN, so we need to set it back to 0
+        if (Float.isNaN(pitch)) {
+            pitch = 0;
+        }
+
+        if (pitch == Float.POSITIVE_INFINITY || pitch == Float.NEGATIVE_INFINITY) {
+            if (this instanceof ServerPlayer) {
+                this.level.getCraftServer().getLogger().warning(this.getScoreboardName() + " was caught trying to crash the server with an invalid pitch");
+                ((CraftPlayer) this.getBukkitEntity()).kickPlayer("Infinite pitch (Hacking?)");
+            }
+            pitch = 0;
+        }
+        // CraftBukkit end
+
         this.setYRot(yaw % 360.0F);
         this.setXRot(pitch % 360.0F);
     }
@@ -426,8 +694,8 @@
     }
 
     public void setPos(double x, double y, double z) {
-        this.setPosRaw(x, y, z);
-        this.setBoundingBox(this.makeBoundingBox());
+        this.setPosRaw(x, y, z, true); // Paper - Block invalid positions and bounding box; force update
+        // this.setBoundingBox(this.makeBoundingBox()); // Paper - Block invalid positions and bounding box; move into setPosRaw
     }
 
     protected final AABB makeBoundingBox() {
@@ -462,10 +730,20 @@
         this.baseTick();
     }
 
+    // CraftBukkit start
+    public void postTick() {
+        // No clean way to break out of ticking once the entity has been copied to a new world, so instead we move the portalling later in the tick cycle
+        if (!(this instanceof ServerPlayer) && this.isAlive()) { // Paper - don't attempt to teleport dead entities
+            this.handlePortal();
+        }
+    }
+    // CraftBukkit end
+
     public void baseTick() {
         ProfilerFiller gameprofilerfiller = Profiler.get();
 
         gameprofilerfiller.push("entityBaseTick");
+        if (firstTick && this instanceof net.minecraft.world.entity.NeutralMob neutralMob) neutralMob.tickInitialPersistentAnger(level); // Paper - Prevent entity loading causing async lookups
         this.inBlockState = null;
         if (this.isPassenger() && this.getVehicle().isRemoved()) {
             this.stopRiding();
@@ -475,7 +753,7 @@
             --this.boardingCooldown;
         }
 
-        this.handlePortal();
+        if (this instanceof ServerPlayer) this.handlePortal(); // CraftBukkit - // Moved up to postTick
         if (this.canSpawnSprintParticle()) {
             this.spawnSprintParticle();
         }
@@ -502,7 +780,7 @@
                     this.setRemainingFireTicks(this.remainingFireTicks - 1);
                 }
 
-                if (this.getTicksFrozen() > 0) {
+                if (this.getTicksFrozen() > 0 && !freezeLocked) { // Paper - Freeze Tick Lock API
                     this.setTicksFrozen(0);
                     this.level().levelEvent((Player) null, 1009, this.blockPosition, 1);
                 }
@@ -514,6 +792,10 @@
         if (this.isInLava()) {
             this.lavaHurt();
             this.fallDistance *= 0.5F;
+            // CraftBukkit start
+        } else {
+            this.lastLavaContact = null;
+            // CraftBukkit end
         }
 
         this.checkBelowWorld();
@@ -525,7 +807,7 @@
         world = this.level();
         if (world instanceof ServerLevel worldserver) {
             if (this instanceof Leashable) {
-                Leashable.tickLeash(worldserver, (Entity) ((Leashable) this));
+                Leashable.tickLeash(worldserver, (Entity & Leashable) this); // CraftBukkit - decompile error
             }
         }
 
@@ -537,7 +819,11 @@
     }
 
     public void checkBelowWorld() {
-        if (this.getY() < (double) (this.level().getMinY() - 64)) {
+        // Paper start - Configurable nether ceiling damage
+        if (this.getY() < (double) (this.level.getMinY() - 64) || (this.level.getWorld().getEnvironment() == org.bukkit.World.Environment.NETHER
+            && this.level.paperConfig().environment.netherCeilingVoidDamageHeight.test(v -> this.getY() >= v)
+            && (!(this instanceof Player player) || !player.getAbilities().invulnerable))) {
+            // Paper end - Configurable nether ceiling damage
             this.onBelowWorld();
         }
 
@@ -568,15 +854,32 @@
 
     public void lavaHurt() {
         if (!this.fireImmune()) {
-            this.igniteForSeconds(15.0F);
+            // CraftBukkit start - Fallen in lava TODO: this event spams!
+            if (this instanceof net.minecraft.world.entity.LivingEntity && this.remainingFireTicks <= 0) {
+                // not on fire yet
+                org.bukkit.block.Block damager = (this.lastLavaContact == null) ? null : org.bukkit.craftbukkit.block.CraftBlock.at(this.level, this.lastLavaContact);
+                org.bukkit.entity.Entity damagee = this.getBukkitEntity();
+                EntityCombustEvent combustEvent = new org.bukkit.event.entity.EntityCombustByBlockEvent(damager, damagee, 15);
+                this.level.getCraftServer().getPluginManager().callEvent(combustEvent);
+
+                if (!combustEvent.isCancelled()) {
+                    this.igniteForSeconds(combustEvent.getDuration(), false);
+                }
+            } else {
+                // This will be called every single tick the entity is in lava, so don't throw an event
+                this.igniteForSeconds(15.0F, false);
+            }
+            // CraftBukkit end
             Level world = this.level();
 
             if (world instanceof ServerLevel) {
                 ServerLevel worldserver = (ServerLevel) world;
 
-                if (this.hurtServer(worldserver, this.damageSources().lava(), 4.0F) && this.shouldPlayLavaHurtSound() && !this.isSilent()) {
+                // CraftBukkit start
+                if (this.hurtServer(worldserver, this.damageSources().lava().directBlock(this.level, this.lastLavaContact), 4.0F) && this.shouldPlayLavaHurtSound() && !this.isSilent()) {
                     worldserver.playSound((Player) null, this.getX(), this.getY(), this.getZ(), SoundEvents.GENERIC_BURN, this.getSoundSource(), 0.4F, 2.0F + this.random.nextFloat() * 0.4F);
                 }
+                // CraftBukkit end - we also don't throw an event unless the object in lava is living, to save on some event calls
             }
 
         }
@@ -587,9 +890,25 @@
     }
 
     public final void igniteForSeconds(float seconds) {
-        this.igniteForTicks(Mth.floor(seconds * 20.0F));
+        // CraftBukkit start
+        this.igniteForSeconds(seconds, true);
     }
 
+    public final void igniteForSeconds(float f, boolean callEvent) {
+        if (callEvent) {
+            EntityCombustEvent event = new EntityCombustEvent(this.getBukkitEntity(), f);
+            this.level.getCraftServer().getPluginManager().callEvent(event);
+
+            if (event.isCancelled()) {
+                return;
+            }
+
+            f = event.getDuration();
+        }
+        // CraftBukkit end
+        this.igniteForTicks(Mth.floor(f * 20.0F));
+    }
+
     public void igniteForTicks(int ticks) {
         if (this.remainingFireTicks < ticks) {
             this.setRemainingFireTicks(ticks);
@@ -610,7 +929,7 @@
     }
 
     protected void onBelowWorld() {
-        this.discard();
+        this.discard(EntityRemoveEvent.Cause.OUT_OF_WORLD); // CraftBukkit - add Bukkit remove cause
     }
 
     public boolean isFree(double offsetX, double offsetY, double offsetZ) {
@@ -672,6 +991,7 @@
     }
 
     public void move(MoverType type, Vec3 movement) {
+        final Vec3 originalMovement = movement; // Paper - Expose pre-collision velocity
         if (this.noPhysics) {
             this.setPos(this.getX() + movement.x, this.getY() + movement.y, this.getZ() + movement.z);
         } else {
@@ -747,8 +1067,30 @@
 
                     if (movement.y != vec3d1.y) {
                         block.updateEntityMovementAfterFallOn(this.level(), this);
+                    }
+                }
+
+                // CraftBukkit start
+                if (this.horizontalCollision && this.getBukkitEntity() instanceof Vehicle) {
+                    Vehicle vehicle = (Vehicle) this.getBukkitEntity();
+                    org.bukkit.block.Block bl = this.level.getWorld().getBlockAt(Mth.floor(this.getX()), Mth.floor(this.getY()), Mth.floor(this.getZ()));
+
+                    if (movement.x > vec3d1.x) {
+                        bl = bl.getRelative(BlockFace.EAST);
+                    } else if (movement.x < vec3d1.x) {
+                        bl = bl.getRelative(BlockFace.WEST);
+                    } else if (movement.z > vec3d1.z) {
+                        bl = bl.getRelative(BlockFace.SOUTH);
+                    } else if (movement.z < vec3d1.z) {
+                        bl = bl.getRelative(BlockFace.NORTH);
+                    }
+
+                    if (!bl.getType().isAir()) {
+                        VehicleBlockCollisionEvent event = new VehicleBlockCollisionEvent(vehicle, bl, org.bukkit.craftbukkit.util.CraftVector.toBukkit(originalMovement)); // Paper - Expose pre-collision velocity
+                        this.level.getCraftServer().getPluginManager().callEvent(event);
                     }
                 }
+                // CraftBukkit end
 
                 if (!this.level().isClientSide() || this.isControlledByLocalInstance()) {
                     Entity.MovementEmission entity_movementemission = this.getMovementEmission();
@@ -913,7 +1255,7 @@
     }
 
     protected BlockPos getOnPos(float offset) {
-        if (this.mainSupportingBlockPos.isPresent()) {
+        if (this.mainSupportingBlockPos.isPresent() && this.level().getChunkIfLoadedImmediately(this.mainSupportingBlockPos.get()) != null) { // Paper - ensure no loads
             BlockPos blockposition = (BlockPos) this.mainSupportingBlockPos.get();
 
             if (offset <= 1.0E-5F) {
@@ -1131,8 +1473,22 @@
 
     protected SoundEvent getSwimHighSpeedSplashSound() {
         return SoundEvents.GENERIC_SPLASH;
+    }
+
+    // CraftBukkit start - Add delegate methods
+    public SoundEvent getSwimSound0() {
+        return this.getSwimSound();
     }
 
+    public SoundEvent getSwimSplashSound0() {
+        return this.getSwimSplashSound();
+    }
+
+    public SoundEvent getSwimHighSpeedSplashSound0() {
+        return this.getSwimHighSpeedSplashSound();
+    }
+    // CraftBukkit end
+
     public void recordMovementThroughBlocks(Vec3 oldPos, Vec3 newPos) {
         this.movementThisTick.add(new Entity.Movement(oldPos, newPos));
     }
@@ -1599,6 +1955,7 @@
         this.setXRot(Mth.clamp(pitch, -90.0F, 90.0F) % 360.0F);
         this.yRotO = this.getYRot();
         this.xRotO = this.getXRot();
+        this.setYHeadRot(yaw); // Paper - Update head rotation
     }
 
     public void absMoveTo(double x, double y, double z) {
@@ -1609,6 +1966,7 @@
         this.yo = y;
         this.zo = d4;
         this.setPos(d3, y, d4);
+        if (this.valid) this.level.getChunk((int) Math.floor(this.getX()) >> 4, (int) Math.floor(this.getZ()) >> 4); // CraftBukkit
     }
 
     public void moveTo(Vec3 pos) {
@@ -1628,11 +1986,19 @@
     }
 
     public void moveTo(double x, double y, double z, float yaw, float pitch) {
+        // Paper start - Fix Entity Teleportation and cancel velocity if teleported
+        if (!preserveMotion) {
+            this.deltaMovement = Vec3.ZERO;
+        } else {
+            this.preserveMotion = false;
+        }
+        // Paper end - Fix Entity Teleportation and cancel velocity if teleported
         this.setPosRaw(x, y, z);
         this.setYRot(yaw);
         this.setXRot(pitch);
         this.setOldPosAndRot();
         this.reapplyPosition();
+        this.setYHeadRot(yaw); // Paper - Update head rotation
     }
 
     public final void setOldPosAndRot() {
@@ -1701,6 +2067,7 @@
     public void push(Entity entity) {
         if (!this.isPassengerOfSameVehicle(entity)) {
             if (!entity.noPhysics && !this.noPhysics) {
+                if (this.level.paperConfig().collisions.onlyPlayersCollide && !(entity instanceof ServerPlayer || this instanceof ServerPlayer)) return; // Paper - Collision option for requiring a player participant
                 double d0 = entity.getX() - this.getX();
                 double d1 = entity.getZ() - this.getZ();
                 double d2 = Mth.absMax(d0, d1);
@@ -1737,7 +2104,21 @@
     }
 
     public void push(double deltaX, double deltaY, double deltaZ) {
-        this.setDeltaMovement(this.getDeltaMovement().add(deltaX, deltaY, deltaZ));
+        // Paper start - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
+        this.push(deltaX, deltaY, deltaZ, null);
+    }
+
+    public void push(double deltaX, double deltaY, double deltaZ, @Nullable Entity pushingEntity) {
+        org.bukkit.util.Vector delta = new org.bukkit.util.Vector(deltaX, deltaY, deltaZ);
+        if (pushingEntity != null) {
+            io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent event = new io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent(this.getBukkitEntity(), io.papermc.paper.event.entity.EntityKnockbackEvent.Cause.PUSH, pushingEntity.getBukkitEntity(), delta);
+            if (!event.callEvent()) {
+                return;
+            }
+            delta = event.getKnockback();
+        }
+        this.setDeltaMovement(this.getDeltaMovement().add(delta.getX(), delta.getY(), delta.getZ()));
+        // Paper end - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
         this.hasImpulse = true;
     }
 
@@ -1858,9 +2239,21 @@
     }
 
     public boolean isPushable() {
+        // Paper start - Climbing should not bypass cramming gamerule
+        return isCollidable(false);
+    }
+
+    public boolean isCollidable(boolean ignoreClimbing) {
+        // Paper end - Climbing should not bypass cramming gamerule
         return false;
     }
 
+    // CraftBukkit start - collidable API
+    public boolean canCollideWithBukkit(Entity entity) {
+        return this.isPushable();
+    }
+    // CraftBukkit end
+
     public void awardKillScore(Entity entityKilled, DamageSource damageSource) {
         if (entityKilled instanceof ServerPlayer) {
             CriteriaTriggers.ENTITY_KILLED_PLAYER.trigger((ServerPlayer) entityKilled, this, damageSource);
@@ -1889,74 +2282,133 @@
     }
 
     public boolean saveAsPassenger(CompoundTag nbt) {
+        // CraftBukkit start - allow excluding certain data when saving
+        return this.saveAsPassenger(nbt, true);
+    }
+
+    public boolean saveAsPassenger(CompoundTag nbttagcompound, boolean includeAll) {
+        // CraftBukkit end
         if (this.removalReason != null && !this.removalReason.shouldSave()) {
             return false;
         } else {
             String s = this.getEncodeId();
 
-            if (s == null) {
+            if (!this.persist || s == null) { // CraftBukkit - persist flag
                 return false;
             } else {
-                nbt.putString("id", s);
-                this.saveWithoutId(nbt);
+                nbttagcompound.putString("id", s);
+                this.saveWithoutId(nbttagcompound, includeAll); // CraftBukkit - pass on includeAll
                 return true;
             }
         }
     }
 
+    // Paper start - Entity serialization api
+    public boolean serializeEntity(CompoundTag compound) {
+        List<Entity> pass = new java.util.ArrayList<>(this.getPassengers());
+        this.passengers = ImmutableList.of();
+        boolean result = save(compound);
+        this.passengers = ImmutableList.copyOf(pass);
+        return result;
+    }
+    // Paper end - Entity serialization api
     public boolean save(CompoundTag nbt) {
         return this.isPassenger() ? false : this.saveAsPassenger(nbt);
     }
 
     public CompoundTag saveWithoutId(CompoundTag nbt) {
+        // CraftBukkit start - allow excluding certain data when saving
+        return this.saveWithoutId(nbt, true);
+    }
+
+    public CompoundTag saveWithoutId(CompoundTag nbttagcompound, boolean includeAll) {
+        // CraftBukkit end
         try {
-            if (this.vehicle != null) {
-                nbt.put("Pos", this.newDoubleList(this.vehicle.getX(), this.getY(), this.vehicle.getZ()));
-            } else {
-                nbt.put("Pos", this.newDoubleList(this.getX(), this.getY(), this.getZ()));
+            // CraftBukkit start - selectively save position
+            if (includeAll) {
+                if (this.vehicle != null) {
+                    nbttagcompound.put("Pos", this.newDoubleList(this.vehicle.getX(), this.getY(), this.vehicle.getZ()));
+                } else {
+                    nbttagcompound.put("Pos", this.newDoubleList(this.getX(), this.getY(), this.getZ()));
+                }
             }
+            // CraftBukkit end
 
             Vec3 vec3d = this.getDeltaMovement();
 
-            nbt.put("Motion", this.newDoubleList(vec3d.x, vec3d.y, vec3d.z));
-            nbt.put("Rotation", this.newFloatList(this.getYRot(), this.getXRot()));
-            nbt.putFloat("FallDistance", this.fallDistance);
-            nbt.putShort("Fire", (short) this.remainingFireTicks);
-            nbt.putShort("Air", (short) this.getAirSupply());
-            nbt.putBoolean("OnGround", this.onGround());
-            nbt.putBoolean("Invulnerable", this.invulnerable);
-            nbt.putInt("PortalCooldown", this.portalCooldown);
-            nbt.putUUID("UUID", this.getUUID());
+            nbttagcompound.put("Motion", this.newDoubleList(vec3d.x, vec3d.y, vec3d.z));
+
+            // CraftBukkit start - Checking for NaN pitch/yaw and resetting to zero
+            // TODO: make sure this is the best way to address this.
+            if (Float.isNaN(this.yRot)) {
+                this.yRot = 0;
+            }
+
+            if (Float.isNaN(this.xRot)) {
+                this.xRot = 0;
+            }
+            // CraftBukkit end
+
+            nbttagcompound.put("Rotation", this.newFloatList(this.getYRot(), this.getXRot()));
+            nbttagcompound.putFloat("FallDistance", this.fallDistance);
+            nbttagcompound.putShort("Fire", (short) this.remainingFireTicks);
+            nbttagcompound.putShort("Air", (short) this.getAirSupply());
+            nbttagcompound.putBoolean("OnGround", this.onGround());
+            nbttagcompound.putBoolean("Invulnerable", this.invulnerable);
+            nbttagcompound.putInt("PortalCooldown", this.portalCooldown);
+            // CraftBukkit start - selectively save uuid and world
+            if (includeAll) {
+                nbttagcompound.putUUID("UUID", this.getUUID());
+                // PAIL: Check above UUID reads 1.8 properly, ie: UUIDMost / UUIDLeast
+                nbttagcompound.putLong("WorldUUIDLeast", ((ServerLevel) this.level).getWorld().getUID().getLeastSignificantBits());
+                nbttagcompound.putLong("WorldUUIDMost", ((ServerLevel) this.level).getWorld().getUID().getMostSignificantBits());
+            }
+            nbttagcompound.putInt("Bukkit.updateLevel", Entity.CURRENT_LEVEL);
+            if (!this.persist) {
+                nbttagcompound.putBoolean("Bukkit.persist", this.persist);
+            }
+            if (!this.visibleByDefault) {
+                nbttagcompound.putBoolean("Bukkit.visibleByDefault", this.visibleByDefault);
+            }
+            if (this.persistentInvisibility) {
+                nbttagcompound.putBoolean("Bukkit.invisible", this.persistentInvisibility);
+            }
+            // SPIGOT-6907: re-implement LivingEntity#setMaximumAir()
+            if (this.maxAirTicks != this.getDefaultMaxAirSupply()) {
+                nbttagcompound.putInt("Bukkit.MaxAirSupply", this.getMaxAirSupply());
+            }
+            nbttagcompound.putInt("Spigot.ticksLived", this.tickCount);
+            // CraftBukkit end
             Component ichatbasecomponent = this.getCustomName();
 
             if (ichatbasecomponent != null) {
-                nbt.putString("CustomName", Component.Serializer.toJson(ichatbasecomponent, this.registryAccess()));
+                nbttagcompound.putString("CustomName", Component.Serializer.toJson(ichatbasecomponent, this.registryAccess()));
             }
 
             if (this.isCustomNameVisible()) {
-                nbt.putBoolean("CustomNameVisible", this.isCustomNameVisible());
+                nbttagcompound.putBoolean("CustomNameVisible", this.isCustomNameVisible());
             }
 
             if (this.isSilent()) {
-                nbt.putBoolean("Silent", this.isSilent());
+                nbttagcompound.putBoolean("Silent", this.isSilent());
             }
 
             if (this.isNoGravity()) {
-                nbt.putBoolean("NoGravity", this.isNoGravity());
+                nbttagcompound.putBoolean("NoGravity", this.isNoGravity());
             }
 
             if (this.hasGlowingTag) {
-                nbt.putBoolean("Glowing", true);
+                nbttagcompound.putBoolean("Glowing", true);
             }
 
             int i = this.getTicksFrozen();
 
             if (i > 0) {
-                nbt.putInt("TicksFrozen", this.getTicksFrozen());
+                nbttagcompound.putInt("TicksFrozen", this.getTicksFrozen());
             }
 
             if (this.hasVisualFire) {
-                nbt.putBoolean("HasVisualFire", this.hasVisualFire);
+                nbttagcompound.putBoolean("HasVisualFire", this.hasVisualFire);
             }
 
             ListTag nbttaglist;
@@ -1972,10 +2424,10 @@
                     nbttaglist.add(StringTag.valueOf(s));
                 }
 
-                nbt.put("Tags", nbttaglist);
+                nbttagcompound.put("Tags", nbttaglist);
             }
 
-            this.addAdditionalSaveData(nbt);
+            this.addAdditionalSaveData(nbttagcompound, includeAll); // CraftBukkit - pass on includeAll
             if (this.isVehicle()) {
                 nbttaglist = new ListTag();
                 iterator = this.getPassengers().iterator();
@@ -1984,17 +2436,44 @@
                     Entity entity = (Entity) iterator.next();
                     CompoundTag nbttagcompound1 = new CompoundTag();
 
-                    if (entity.saveAsPassenger(nbttagcompound1)) {
+                    if (entity.saveAsPassenger(nbttagcompound1, includeAll)) { // CraftBukkit - pass on includeAll
                         nbttaglist.add(nbttagcompound1);
                     }
                 }
 
                 if (!nbttaglist.isEmpty()) {
-                    nbt.put("Passengers", nbttaglist);
+                    nbttagcompound.put("Passengers", nbttaglist);
                 }
             }
 
-            return nbt;
+            // CraftBukkit start - stores eventually existing bukkit values
+            if (this.bukkitEntity != null) {
+                this.bukkitEntity.storeBukkitValues(nbttagcompound);
+            }
+            // CraftBukkit end
+            // Paper start
+            if (this.origin != null) {
+                UUID originWorld = this.originWorld != null ? this.originWorld : this.level != null ? this.level.getWorld().getUID() : null;
+                if (originWorld != null) {
+                    nbttagcompound.putUUID("Paper.OriginWorld", originWorld);
+                }
+                nbttagcompound.put("Paper.Origin", this.newDoubleList(origin.getX(), origin.getY(), origin.getZ()));
+            }
+            if (spawnReason != null) {
+                nbttagcompound.putString("Paper.SpawnReason", spawnReason.name());
+            }
+            // Save entity's from mob spawner status
+            if (spawnedViaMobSpawner) {
+                nbttagcompound.putBoolean("Paper.FromMobSpawner", true);
+            }
+            if (fromNetherPortal) {
+                nbttagcompound.putBoolean("Paper.FromNetherPortal", true);
+            }
+            if (freezeLocked) {
+                nbttagcompound.putBoolean("Paper.FreezeLock", true);
+            }
+            // Paper end
+            return nbttagcompound;
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.forThrowable(throwable, "Saving entity NBT");
             CrashReportCategory crashreportsystemdetails = crashreport.addCategory("Entity being saved");
@@ -2080,6 +2559,71 @@
             } else {
                 throw new IllegalStateException("Entity has invalid position");
             }
+
+            // CraftBukkit start
+            // Spigot start
+            if (this instanceof net.minecraft.world.entity.LivingEntity) {
+                this.tickCount = nbt.getInt("Spigot.ticksLived");
+            }
+            // Spigot end
+            this.persist = !nbt.contains("Bukkit.persist") || nbt.getBoolean("Bukkit.persist");
+            this.visibleByDefault = !nbt.contains("Bukkit.visibleByDefault") || nbt.getBoolean("Bukkit.visibleByDefault");
+            // SPIGOT-6907: re-implement LivingEntity#setMaximumAir()
+            if (nbt.contains("Bukkit.MaxAirSupply")) {
+                this.maxAirTicks = nbt.getInt("Bukkit.MaxAirSupply");
+            }
+            // CraftBukkit end
+
+            // CraftBukkit start
+            // Paper - move world parsing/loading to PlayerList#placeNewPlayer
+            this.getBukkitEntity().readBukkitValues(nbt);
+            if (nbt.contains("Bukkit.invisible")) {
+                boolean bukkitInvisible = nbt.getBoolean("Bukkit.invisible");
+                this.setInvisible(bukkitInvisible);
+                this.persistentInvisibility = bukkitInvisible;
+            }
+            // CraftBukkit end
+
+            // Paper start
+            ListTag originTag = nbt.getList("Paper.Origin", net.minecraft.nbt.Tag.TAG_DOUBLE);
+            if (!originTag.isEmpty()) {
+                UUID originWorld = null;
+                if (nbt.contains("Paper.OriginWorld")) {
+                    originWorld = nbt.getUUID("Paper.OriginWorld");
+                } else if (this.level != null) {
+                    originWorld = this.level.getWorld().getUID();
+                }
+                this.originWorld = originWorld;
+                origin = new org.bukkit.util.Vector(originTag.getDouble(0), originTag.getDouble(1), originTag.getDouble(2));
+            }
+
+            spawnedViaMobSpawner = nbt.getBoolean("Paper.FromMobSpawner"); // Restore entity's from mob spawner status
+            fromNetherPortal = nbt.getBoolean("Paper.FromNetherPortal");
+            if (nbt.contains("Paper.SpawnReason")) {
+                String spawnReasonName = nbt.getString("Paper.SpawnReason");
+                try {
+                    spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.valueOf(spawnReasonName);
+                } catch (Exception ignored) {
+                    LOGGER.error("Unknown SpawnReason " + spawnReasonName + " for " + this);
+                }
+            }
+            if (spawnReason == null) {
+                if (spawnedViaMobSpawner) {
+                    spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER;
+                } else if (this instanceof Mob && (this instanceof net.minecraft.world.entity.animal.Animal || this instanceof net.minecraft.world.entity.animal.AbstractFish) && !((Mob) this).removeWhenFarAway(0.0)) {
+                    if (!nbt.getBoolean("PersistenceRequired")) {
+                        spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.NATURAL;
+                    }
+                }
+            }
+            if (spawnReason == null) {
+                spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT;
+            }
+            if (nbt.contains("Paper.FreezeLock")) {
+                freezeLocked = nbt.getBoolean("Paper.FreezeLock");
+            }
+            // Paper end
+
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.forThrowable(throwable, "Loading entity NBT");
             CrashReportCategory crashreportsystemdetails = crashreport.addCategory("Entity being loaded");
@@ -2101,6 +2645,12 @@
         return entitytypes.canSerialize() && minecraftkey != null ? minecraftkey.toString() : null;
     }
 
+    // CraftBukkit start - allow excluding certain data when saving
+    protected void addAdditionalSaveData(CompoundTag nbttagcompound, boolean includeAll) {
+        this.addAdditionalSaveData(nbttagcompound);
+    }
+    // CraftBukkit end
+
     protected abstract void readAdditionalSaveData(CompoundTag nbt);
 
     protected abstract void addAdditionalSaveData(CompoundTag nbt);
@@ -2153,9 +2703,31 @@
         if (stack.isEmpty()) {
             return null;
         } else {
-            ItemEntity entityitem = new ItemEntity(world, this.getX(), this.getY() + (double) yOffset, this.getZ(), stack);
+            // CraftBukkit start - Capture drops for death event
+            if (this instanceof net.minecraft.world.entity.LivingEntity && !((net.minecraft.world.entity.LivingEntity) this).forceDrops) {
+                ((net.minecraft.world.entity.LivingEntity) this).drops.add(org.bukkit.craftbukkit.inventory.CraftItemStack.asCraftMirror(stack)); // Paper - mirror so we can destroy it later
+                return null;
+            }
+            // CraftBukkit end
+            ItemEntity entityitem = new ItemEntity(world, this.getX(), this.getY() + (double) yOffset, this.getZ(), stack.copy()); // Paper - copy so we can destroy original
+            stack.setCount(0); // Paper - destroy this item - if this ever leaks due to game bugs, ensure it doesn't dupe
 
             entityitem.setDefaultPickUpDelay();
+            // Paper start - Call EntityDropItemEvent
+            return this.spawnAtLocation(world, entityitem);
+        }
+    }
+    @Nullable
+    public ItemEntity spawnAtLocation(ServerLevel world, ItemEntity entityitem) {
+        {
+            // Paper end - Call EntityDropItemEvent
+            // CraftBukkit start
+            EntityDropItemEvent event = new EntityDropItemEvent(this.getBukkitEntity(), (org.bukkit.entity.Item) entityitem.getBukkitEntity());
+            Bukkit.getPluginManager().callEvent(event);
+            if (event.isCancelled()) {
+                return null;
+            }
+            // CraftBukkit end
             world.addFreshEntity(entityitem);
             return entityitem;
         }
@@ -2184,7 +2756,16 @@
         if (this.isAlive() && this instanceof Leashable leashable) {
             if (leashable.getLeashHolder() == player) {
                 if (!this.level().isClientSide()) {
-                    if (player.hasInfiniteMaterials()) {
+                    // CraftBukkit start - fire PlayerUnleashEntityEvent
+                    // Paper start - Expand EntityUnleashEvent
+                    org.bukkit.event.player.PlayerUnleashEntityEvent event = CraftEventFactory.callPlayerUnleashEntityEvent(this, player, hand, !player.hasInfiniteMaterials());
+                    if (event.isCancelled()) {
+                        // Paper end - Expand EntityUnleashEvent
+                        ((ServerPlayer) player).connection.send(new ClientboundSetEntityLinkPacket(this, leashable.getLeashHolder()));
+                        return InteractionResult.PASS;
+                    }
+                    // CraftBukkit end
+                    if (!event.isDropLeash()) { // Paper - Expand EntityUnleashEvent
                         leashable.removeLeash();
                     } else {
                         leashable.dropLeash();
@@ -2200,6 +2781,14 @@
 
             if (itemstack.is(Items.LEAD) && leashable.canHaveALeashAttachedToIt()) {
                 if (!this.level().isClientSide()) {
+                    // CraftBukkit start - fire PlayerLeashEntityEvent
+                    if (CraftEventFactory.callPlayerLeashEntityEvent(this, player, player, hand).isCancelled()) {
+                        // ((ServerPlayer) player).resendItemInHands(); // SPIGOT-7615: Resend to fix client desync with used item // Paper - Fix inventory desync
+                        ((ServerPlayer) player).connection.send(new ClientboundSetEntityLinkPacket(this, leashable.getLeashHolder()));
+                        player.containerMenu.sendAllDataToRemote(); // Paper - Fix inventory desync
+                        return InteractionResult.PASS;
+                    }
+                    // CraftBukkit end
                     leashable.setLeashedTo(player, true);
                 }
 
@@ -2265,15 +2854,15 @@
     }
 
     public boolean showVehicleHealth() {
-        return this instanceof LivingEntity;
+        return this instanceof net.minecraft.world.entity.LivingEntity;
     }
 
     public boolean startRiding(Entity entity, boolean force) {
-        if (entity == this.vehicle) {
+        if (entity == this.vehicle || entity.level != this.level) { // Paper - Ensure entity passenger world matches ridden entity (bad plugins)
             return false;
         } else if (!entity.couldAcceptPassenger()) {
             return false;
-        } else if (!this.level().isClientSide() && !entity.type.canSerialize()) {
+        } else if (!force && !this.level().isClientSide() && !entity.type.canSerialize()) { // SPIGOT-7947: Allow force riding all entities
             return false;
         } else {
             for (Entity entity1 = entity; entity1.vehicle != null; entity1 = entity1.vehicle) {
@@ -2285,11 +2874,32 @@
             if (!force && (!this.canRide(entity) || !entity.canAddPassenger(this))) {
                 return false;
             } else {
+                // CraftBukkit start
+                if (entity.getBukkitEntity() instanceof Vehicle && this.getBukkitEntity() instanceof LivingEntity) {
+                    VehicleEnterEvent event = new VehicleEnterEvent((Vehicle) entity.getBukkitEntity(), this.getBukkitEntity());
+                    // Suppress during worldgen
+                    if (this.valid) {
+                        Bukkit.getPluginManager().callEvent(event);
+                    }
+                    if (event.isCancelled()) {
+                        return false;
+                    }
+                }
+
+                EntityMountEvent event = new EntityMountEvent(this.getBukkitEntity(), entity.getBukkitEntity());
+                // Suppress during worldgen
+                if (this.valid) {
+                    Bukkit.getPluginManager().callEvent(event);
+                }
+                if (event.isCancelled()) {
+                    return false;
+                }
+                // CraftBukkit end
                 if (this.isPassenger()) {
                     this.stopRiding();
                 }
 
-                this.setPose(Pose.STANDING);
+                this.setPose(net.minecraft.world.entity.Pose.STANDING);
                 this.vehicle = entity;
                 this.vehicle.addPassenger(this);
                 entity.getIndirectPassengersStream().filter((entity2) -> {
@@ -2314,19 +2924,30 @@
     }
 
     public void removeVehicle() {
+        // Paper start - Force entity dismount during teleportation
+        this.removeVehicle(false);
+    }
+    public void removeVehicle(boolean suppressCancellation) {
+        // Paper end - Force entity dismount during teleportation
         if (this.vehicle != null) {
             Entity entity = this.vehicle;
 
             this.vehicle = null;
-            entity.removePassenger(this);
+            if (!entity.removePassenger(this, suppressCancellation)) this.vehicle = entity; // CraftBukkit // Paper - Force entity dismount during teleportation
         }
 
     }
 
     public void stopRiding() {
-        this.removeVehicle();
+        // Paper start - Force entity dismount during teleportation
+        this.stopRiding(false);
     }
 
+    public void stopRiding(boolean suppressCancellation) {
+        this.removeVehicle(suppressCancellation);
+        // Paper end - Force entity dismount during teleportation
+    }
+
     protected void addPassenger(Entity passenger) {
         if (passenger.getVehicle() != this) {
             throw new IllegalStateException("Use x.startRiding(y), not y.addPassenger(x)");
@@ -2349,21 +2970,53 @@
         }
     }
 
-    protected void removePassenger(Entity passenger) {
-        if (passenger.getVehicle() == this) {
+    // Paper start - Force entity dismount during teleportation
+    protected boolean removePassenger(Entity entity) { return removePassenger(entity, false);}
+    protected boolean removePassenger(Entity entity, boolean suppressCancellation) { // CraftBukkit
+        // Paper end - Force entity dismount during teleportation
+        if (entity.getVehicle() == this) {
             throw new IllegalStateException("Use x.stopRiding(y), not y.removePassenger(x)");
         } else {
-            if (this.passengers.size() == 1 && this.passengers.get(0) == passenger) {
+            // CraftBukkit start
+            CraftEntity craft = (CraftEntity) entity.getBukkitEntity().getVehicle();
+            Entity orig = craft == null ? null : craft.getHandle();
+            if (this.getBukkitEntity() instanceof Vehicle && entity.getBukkitEntity() instanceof LivingEntity) {
+                VehicleExitEvent event = new VehicleExitEvent(
+                        (Vehicle) this.getBukkitEntity(),
+                        (LivingEntity) entity.getBukkitEntity(), !suppressCancellation // Paper - Force entity dismount during teleportation
+                );
+                // Suppress during worldgen
+                if (this.valid) {
+                    Bukkit.getPluginManager().callEvent(event);
+                }
+                CraftEntity craftn = (CraftEntity) entity.getBukkitEntity().getVehicle();
+                Entity n = craftn == null ? null : craftn.getHandle();
+                if (event.isCancelled() || n != orig) {
+                    return false;
+                }
+            }
+
+            EntityDismountEvent event = new EntityDismountEvent(entity.getBukkitEntity(), this.getBukkitEntity(), !suppressCancellation); // Paper - Force entity dismount during teleportation
+            // Suppress during worldgen
+            if (this.valid) {
+                Bukkit.getPluginManager().callEvent(event);
+            }
+            if (event.isCancelled()) {
+                return false;
+            }
+            // CraftBukkit end
+            if (this.passengers.size() == 1 && this.passengers.get(0) == entity) {
                 this.passengers = ImmutableList.of();
             } else {
                 this.passengers = (ImmutableList) this.passengers.stream().filter((entity1) -> {
-                    return entity1 != passenger;
+                    return entity1 != entity;
                 }).collect(ImmutableList.toImmutableList());
             }
 
-            passenger.boardingCooldown = 60;
-            this.gameEvent(GameEvent.ENTITY_DISMOUNT, passenger);
+            entity.boardingCooldown = 60;
+            this.gameEvent(GameEvent.ENTITY_DISMOUNT, entity);
         }
+        return true; // CraftBukkit
     }
 
     protected boolean canAddPassenger(Entity passenger) {
@@ -2464,7 +3117,7 @@
                     if (teleporttransition != null) {
                         ServerLevel worldserver1 = teleporttransition.newLevel();
 
-                        if (worldserver.getServer().isLevelEnabled(worldserver1) && (worldserver1.dimension() == worldserver.dimension() || this.canTeleport(worldserver, worldserver1))) {
+                        if (this instanceof ServerPlayer || (worldserver1 != null && (worldserver1.dimension() == worldserver.dimension() || this.canTeleport(worldserver, worldserver1)))) { // CraftBukkit - always call event for players
                             this.teleport(teleporttransition);
                         }
                     }
@@ -2547,7 +3200,7 @@
     }
 
     public boolean isCrouching() {
-        return this.hasPose(Pose.CROUCHING);
+        return this.hasPose(net.minecraft.world.entity.Pose.CROUCHING);
     }
 
     public boolean isSprinting() {
@@ -2563,7 +3216,7 @@
     }
 
     public boolean isVisuallySwimming() {
-        return this.hasPose(Pose.SWIMMING);
+        return this.hasPose(net.minecraft.world.entity.Pose.SWIMMING);
     }
 
     public boolean isVisuallyCrawling() {
@@ -2571,6 +3224,13 @@
     }
 
     public void setSwimming(boolean swimming) {
+        // CraftBukkit start
+        if (this.valid && this.isSwimming() != swimming && this instanceof net.minecraft.world.entity.LivingEntity) {
+            if (CraftEventFactory.callToggleSwimEvent((net.minecraft.world.entity.LivingEntity) this, swimming).isCancelled()) {
+                return;
+            }
+        }
+        // CraftBukkit end
         this.setSharedFlag(4, swimming);
     }
 
@@ -2609,6 +3269,7 @@
 
     @Nullable
     public PlayerTeam getTeam() {
+        if (!this.level().paperConfig().scoreboards.allowNonPlayerEntitiesOnScoreboards && !(this instanceof Player)) { return null; } // Paper - Perf: Disable Scoreboards for non players by default
         return this.level().getScoreboard().getPlayersTeam(this.getScoreboardName());
     }
 
@@ -2624,8 +3285,12 @@
         return this.getTeam() != null ? this.getTeam().isAlliedTo(team) : false;
     }
 
+    // CraftBukkit - start
     public void setInvisible(boolean invisible) {
-        this.setSharedFlag(5, invisible);
+        if (!this.persistentInvisibility) { // Prevent Minecraft from removing our invisibility flag
+            this.setSharedFlag(5, invisible);
+        }
+        // CraftBukkit - end
     }
 
     public boolean getSharedFlag(int index) {
@@ -2644,7 +3309,7 @@
     }
 
     public int getMaxAirSupply() {
-        return 300;
+        return this.maxAirTicks; // CraftBukkit - SPIGOT-6907: re-implement LivingEntity#setMaximumAir()
     }
 
     public int getAirSupply() {
@@ -2652,7 +3317,18 @@
     }
 
     public void setAirSupply(int air) {
-        this.entityData.set(Entity.DATA_AIR_SUPPLY_ID, air);
+        // CraftBukkit start
+        EntityAirChangeEvent event = new EntityAirChangeEvent(this.getBukkitEntity(), air);
+        // Suppress during worldgen
+        if (this.valid) {
+            event.getEntity().getServer().getPluginManager().callEvent(event);
+        }
+        if (event.isCancelled() && this.getAirSupply() != air) {
+            this.entityData.markDirty(Entity.DATA_AIR_SUPPLY_ID);
+            return;
+        }
+        this.entityData.set(Entity.DATA_AIR_SUPPLY_ID, event.getAmount());
+        // CraftBukkit end
     }
 
     public int getTicksFrozen() {
@@ -2679,11 +3355,44 @@
 
     public void thunderHit(ServerLevel world, LightningBolt lightning) {
         this.setRemainingFireTicks(this.remainingFireTicks + 1);
+        // CraftBukkit start
+        final org.bukkit.entity.Entity thisBukkitEntity = this.getBukkitEntity();
+        final org.bukkit.entity.Entity stormBukkitEntity = lightning.getBukkitEntity();
+        final PluginManager pluginManager = Bukkit.getPluginManager();
+        // CraftBukkit end
+
         if (this.remainingFireTicks == 0) {
-            this.igniteForSeconds(8.0F);
+            // CraftBukkit start - Call a combust event when lightning strikes
+            EntityCombustByEntityEvent entityCombustEvent = new EntityCombustByEntityEvent(stormBukkitEntity, thisBukkitEntity, 8.0F);
+            pluginManager.callEvent(entityCombustEvent);
+            if (!entityCombustEvent.isCancelled()) {
+                this.igniteForSeconds(entityCombustEvent.getDuration(), false);
+            // Paper start - fix EntityCombustEvent cancellation
+            } else {
+                this.setRemainingFireTicks(this.remainingFireTicks - 1);
+            // Paper end - fix EntityCombustEvent cancellation
+            }
+            // CraftBukkit end
         }
 
-        this.hurtServer(world, this.damageSources().lightningBolt(), 5.0F);
+        // CraftBukkit start
+        if (thisBukkitEntity instanceof Hanging) {
+            HangingBreakByEntityEvent hangingEvent = new HangingBreakByEntityEvent((Hanging) thisBukkitEntity, stormBukkitEntity);
+            pluginManager.callEvent(hangingEvent);
+
+            if (hangingEvent.isCancelled()) {
+                return;
+            }
+        }
+
+        if (this.fireImmune()) {
+            return;
+        }
+
+        if (!this.hurtServer(world, this.damageSources().lightningBolt().customEntityDamager(lightning), 5.0F)) {
+            return;
+        }
+        // CraftBukkit end
     }
 
     public void onAboveBubbleCol(boolean drag) {
@@ -2713,7 +3422,7 @@
         this.resetFallDistance();
     }
 
-    public boolean killedEntity(ServerLevel world, LivingEntity other) {
+    public boolean killedEntity(ServerLevel world, net.minecraft.world.entity.LivingEntity other) {
         return true;
     }
 
@@ -2818,7 +3527,7 @@
     public String toString() {
         String s = this.level() == null ? "~NULL~" : this.level().toString();
 
-        return this.removalReason != null ? String.format(Locale.ROOT, "%s['%s'/%d, l='%s', x=%.2f, y=%.2f, z=%.2f, removed=%s]", this.getClass().getSimpleName(), this.getName().getString(), this.id, s, this.getX(), this.getY(), this.getZ(), this.removalReason) : String.format(Locale.ROOT, "%s['%s'/%d, l='%s', x=%.2f, y=%.2f, z=%.2f]", this.getClass().getSimpleName(), this.getName().getString(), this.id, s, this.getX(), this.getY(), this.getZ());
+        return this.removalReason != null ? String.format(Locale.ROOT, "%s['%s'/%d, uuid='%s', l='%s', x=%.2f, y=%.2f, z=%.2f, cpos=%s, tl=%d, v=%b, removed=%s]", this.getClass().getSimpleName(), this.getName().getString(), this.id, this.uuid, s, this.getX(), this.getY(), this.getZ(), this.chunkPosition(), this.tickCount, this.valid, this.removalReason) : String.format(Locale.ROOT, "%s['%s'/%d, uuid='%s', l='%s', x=%.2f, y=%.2f, z=%.2f, cpos=%s, tl=%d, v=%b]", this.getClass().getSimpleName(), this.getName().getString(), this.id, this.uuid, s, this.getX(), this.getY(), this.getZ(), this.chunkPosition(), this.tickCount, this.valid); // Paper - add more info
     }
 
     public final boolean isInvulnerableToBase(DamageSource damageSource) {
@@ -2838,6 +3547,13 @@
     }
 
     public void restoreFrom(Entity original) {
+        // Paper start - Forward CraftEntity in teleport command
+        CraftEntity bukkitEntity = original.bukkitEntity;
+        if (bukkitEntity != null) {
+            bukkitEntity.setHandle(this);
+            this.bukkitEntity = bukkitEntity;
+        }
+        // Paper end - Forward CraftEntity in teleport command
         CompoundTag nbttagcompound = original.saveWithoutId(new CompoundTag());
 
         nbttagcompound.remove("Dimension");
@@ -2850,8 +3566,57 @@
     public Entity teleport(TeleportTransition teleportTarget) {
         Level world = this.level();
 
+        // Paper start - Fix item duplication and teleport issues
+        if ((!this.isAlive() || !this.valid) && (teleportTarget.newLevel() != world)) {
+            LOGGER.warn("Illegal Entity Teleport " + this + " to " + teleportTarget.newLevel() + ":" + teleportTarget.position(), new Throwable());
+            return null;
+        }
+        // Paper end - Fix item duplication and teleport issues
         if (world instanceof ServerLevel worldserver) {
             if (!this.isRemoved()) {
+                // CraftBukkit start
+                PositionMoveRotation absolutePosition = PositionMoveRotation.calculateAbsolute(PositionMoveRotation.of(this), PositionMoveRotation.of(teleportTarget), teleportTarget.relatives());
+                Vec3 velocity = absolutePosition.deltaMovement(); // Paper
+                Location to = CraftLocation.toBukkit(absolutePosition.position(), teleportTarget.newLevel().getWorld(), absolutePosition.yRot(), absolutePosition.xRot());
+                // Paper start - gateway-specific teleport event
+                final EntityTeleportEvent teleEvent;
+                if (this.portalProcess != null && this.portalProcess.isSamePortal(((net.minecraft.world.level.block.EndGatewayBlock) net.minecraft.world.level.block.Blocks.END_GATEWAY)) && this.level.getBlockEntity(this.portalProcess.getEntryPosition()) instanceof net.minecraft.world.level.block.entity.TheEndGatewayBlockEntity theEndGatewayBlockEntity) {
+                    teleEvent = new com.destroystokyo.paper.event.entity.EntityTeleportEndGatewayEvent(this.getBukkitEntity(), this.getBukkitEntity().getLocation(), to, new org.bukkit.craftbukkit.block.CraftEndGateway(to.getWorld(), theEndGatewayBlockEntity));
+                    teleEvent.callEvent();
+                } else {
+                    teleEvent = CraftEventFactory.callEntityTeleportEvent(this, to);
+                }
+                // Paper end - gateway-specific teleport event
+                if (teleEvent.isCancelled() || teleEvent.getTo() == null) {
+                    return null;
+                }
+                if (!to.equals(teleEvent.getTo())) {
+                    to = teleEvent.getTo();
+                    teleportTarget = new TeleportTransition(((CraftWorld) to.getWorld()).getHandle(), CraftLocation.toVec3D(to), Vec3.ZERO, to.getYaw(), to.getPitch(), teleportTarget.missingRespawnBlock(), teleportTarget.asPassenger(), Set.of(), teleportTarget.postTeleportTransition(), teleportTarget.cause());
+                    // Paper start - Call EntityPortalExitEvent
+                    velocity = Vec3.ZERO;
+                }
+                if (this.portalProcess != null) { // if in a portal
+                    CraftEntity bukkitEntity = this.getBukkitEntity();
+                    org.bukkit.event.entity.EntityPortalExitEvent event = new org.bukkit.event.entity.EntityPortalExitEvent(
+                        bukkitEntity,
+                        bukkitEntity.getLocation(), to.clone(),
+                        bukkitEntity.getVelocity(), org.bukkit.craftbukkit.util.CraftVector.toBukkit(velocity)
+                    );
+                    event.callEvent();
+
+                    // Only change the target if actually needed, since we reset relative flags
+                    if (!event.isCancelled() && event.getTo() != null && (!event.getTo().equals(event.getFrom()) || !event.getAfter().equals(event.getBefore()))) {
+                        to = event.getTo().clone();
+                        velocity = org.bukkit.craftbukkit.util.CraftVector.toNMS(event.getAfter());
+                        teleportTarget = new TeleportTransition(((CraftWorld) to.getWorld()).getHandle(), CraftLocation.toVec3D(to), velocity, to.getYaw(), to.getPitch(), teleportTarget.missingRespawnBlock(), teleportTarget.asPassenger(), Set.of(), teleportTarget.postTeleportTransition(), teleportTarget.cause());
+                    }
+                }
+                if (this.isRemoved()) {
+                    return null;
+                }
+                // Paper end - Call EntityPortalExitEvent
+                // CraftBukkit end
                 ServerLevel worldserver1 = teleportTarget.newLevel();
                 boolean flag = worldserver1.dimension() != worldserver.dimension();
 
@@ -2918,10 +3683,19 @@
             gameprofilerfiller.pop();
             return null;
         } else {
+            // Paper start - Fix item duplication and teleport issues
+            if (this instanceof Leashable leashable) {
+                leashable.dropLeash(); // Paper drop lead
+            }
+            // Paper end - Fix item duplication and teleport issues
             entity.restoreFrom(this);
             this.removeAfterChangingDimensions();
+            // CraftBukkit start - Forward the CraftEntity to the new entity
+            //this.getBukkitEntity().setHandle(entity);
+            //entity.bukkitEntity = this.getBukkitEntity(); // Paper - forward CraftEntity in teleport command; moved to Entity#restoreFrom
+            // CraftBukkit end
             entity.teleportSetPosition(PositionMoveRotation.of(teleportTarget), teleportTarget.relatives());
-            world.addDuringTeleport(entity);
+            if (this.inWorld) world.addDuringTeleport(entity); // CraftBukkit - Don't spawn the new entity if the current entity isn't spawned
             Iterator iterator1 = list1.iterator();
 
             while (iterator1.hasNext()) {
@@ -2947,7 +3721,7 @@
     }
 
     private void sendTeleportTransitionToRidingPlayers(TeleportTransition teleportTarget) {
-        LivingEntity entityliving = this.getControllingPassenger();
+        net.minecraft.world.entity.LivingEntity entityliving = this.getControllingPassenger();
         Iterator iterator = this.getIndirectPassengers().iterator();
 
         while (iterator.hasNext()) {
@@ -2995,9 +3769,17 @@
     }
 
     protected void removeAfterChangingDimensions() {
-        this.setRemoved(Entity.RemovalReason.CHANGED_DIMENSION);
-        if (this instanceof Leashable leashable) {
-            leashable.removeLeash();
+        this.setRemoved(Entity.RemovalReason.CHANGED_DIMENSION, null); // CraftBukkit - add Bukkit remove cause
+        if (this instanceof Leashable leashable && leashable.isLeashed()) { // Paper - only call if it is leashed
+            // Paper start - Expand EntityUnleashEvent
+            final EntityUnleashEvent event = new EntityUnleashEvent(this.getBukkitEntity(), UnleashReason.UNKNOWN, false); // CraftBukkit
+            event.callEvent();
+            if (!event.isDropLeash()) {
+                leashable.removeLeash();
+            } else {
+                leashable.dropLeash();
+            }
+            // Paper end - Expand EntityUnleashEvent
         }
 
     }
@@ -3006,11 +3788,34 @@
         return PortalShape.getRelativePosition(portalRect, portalAxis, this.position(), this.getDimensions(this.getPose()));
     }
 
+    // CraftBukkit start
+    public CraftPortalEvent callPortalEvent(Entity entity, Location exit, PlayerTeleportEvent.TeleportCause cause, int searchRadius, int creationRadius) {
+        org.bukkit.entity.Entity bukkitEntity = entity.getBukkitEntity();
+        Location enter = bukkitEntity.getLocation();
+
+        // Paper start
+        final org.bukkit.PortalType portalType = switch (cause) {
+            case END_PORTAL -> org.bukkit.PortalType.ENDER;
+            case NETHER_PORTAL -> org.bukkit.PortalType.NETHER;
+            case END_GATEWAY -> org.bukkit.PortalType.END_GATEWAY; // not actually used yet
+            default -> org.bukkit.PortalType.CUSTOM;
+        };
+        EntityPortalEvent event = new EntityPortalEvent(bukkitEntity, enter, exit, searchRadius, true, creationRadius, portalType);
+        // Paper end
+        event.getEntity().getServer().getPluginManager().callEvent(event);
+        if (event.isCancelled() || event.getTo() == null || event.getTo().getWorld() == null || !entity.isAlive()) {
+            return null;
+        }
+        return new CraftPortalEvent(event);
+    }
+    // CraftBukkit end
+
     public boolean canUsePortal(boolean allowVehicles) {
         return (allowVehicles || !this.isPassenger()) && this.isAlive();
     }
 
     public boolean canTeleport(Level from, Level to) {
+        if (!this.isAlive() || !this.valid) return false; // Paper - Fix item duplication and teleport issues
         if (from.dimension() == Level.END && to.dimension() == Level.OVERWORLD) {
             Iterator iterator = this.getPassengers().iterator();
 
@@ -3134,10 +3939,16 @@
         return (Boolean) this.entityData.get(Entity.DATA_CUSTOM_NAME_VISIBLE);
     }
 
-    public boolean teleportTo(ServerLevel world, double destX, double destY, double destZ, Set<Relative> flags, float yaw, float pitch, boolean resetCamera) {
-        float f2 = Mth.clamp(pitch, -90.0F, 90.0F);
-        Entity entity = this.teleport(new TeleportTransition(world, new Vec3(destX, destY, destZ), Vec3.ZERO, yaw, f2, flags, TeleportTransition.DO_NOTHING));
+    // CraftBukkit start
+    public final boolean teleportTo(ServerLevel world, double destX, double destY, double destZ, Set<Relative> flags, float yaw, float pitch, boolean resetCamera) {
+        return this.teleportTo(world, destX, destY, destZ, flags, yaw, pitch, resetCamera, PlayerTeleportEvent.TeleportCause.UNKNOWN);
+    }
 
+    public boolean teleportTo(ServerLevel worldserver, double d0, double d1, double d2, Set<Relative> set, float f, float f1, boolean flag, org.bukkit.event.player.PlayerTeleportEvent.TeleportCause cause) {
+        float f2 = Mth.clamp(f1, -90.0F, 90.0F);
+        Entity entity = this.teleport(new TeleportTransition(worldserver, new Vec3(d0, d1, d2), Vec3.ZERO, f, f2, set, TeleportTransition.DO_NOTHING, cause));
+        // CraftBukkit end
+
         return entity != null;
     }
 
@@ -3187,7 +3998,7 @@
     /** @deprecated */
     @Deprecated
     protected void fixupDimensions() {
-        Pose entitypose = this.getPose();
+        net.minecraft.world.entity.Pose entitypose = this.getPose();
         EntityDimensions entitysize = this.getDimensions(entitypose);
 
         this.dimensions = entitysize;
@@ -3196,7 +4007,7 @@
 
     public void refreshDimensions() {
         EntityDimensions entitysize = this.dimensions;
-        Pose entitypose = this.getPose();
+        net.minecraft.world.entity.Pose entitypose = this.getPose();
         EntityDimensions entitysize1 = this.getDimensions(entitypose);
 
         this.dimensions = entitysize1;
@@ -3258,10 +4069,29 @@
     }
 
     public final void setBoundingBox(AABB boundingBox) {
-        this.bb = boundingBox;
+        // CraftBukkit start - block invalid bounding boxes
+        double minX = boundingBox.minX,
+                minY = boundingBox.minY,
+                minZ = boundingBox.minZ,
+                maxX = boundingBox.maxX,
+                maxY = boundingBox.maxY,
+                maxZ = boundingBox.maxZ;
+        double len = boundingBox.maxX - boundingBox.minX;
+        if (len < 0) maxX = minX;
+        if (len > 64) maxX = minX + 64.0;
+
+        len = boundingBox.maxY - boundingBox.minY;
+        if (len < 0) maxY = minY;
+        if (len > 64) maxY = minY + 64.0;
+
+        len = boundingBox.maxZ - boundingBox.minZ;
+        if (len < 0) maxZ = minZ;
+        if (len > 64) maxZ = minZ + 64.0;
+        this.bb = new AABB(minX, minY, minZ, maxX, maxY, maxZ);
+        // CraftBukkit end
     }
 
-    public final float getEyeHeight(Pose pose) {
+    public final float getEyeHeight(net.minecraft.world.entity.Pose pose) {
         return this.getDimensions(pose).eyeHeight();
     }
 
@@ -3300,7 +4130,14 @@
 
     public void startSeenByPlayer(ServerPlayer player) {}
 
-    public void stopSeenByPlayer(ServerPlayer player) {}
+    // Paper start - entity tracking events
+    public void stopSeenByPlayer(ServerPlayer player) {
+        // Since this event cannot be cancelled, we should call it here to catch all "un-tracks"
+        if (io.papermc.paper.event.player.PlayerUntrackEntityEvent.getHandlerList().getRegisteredListeners().length > 0) {
+            new io.papermc.paper.event.player.PlayerUntrackEntityEvent(player.getBukkitEntity(), this.getBukkitEntity()).callEvent();
+        }
+    }
+    // Paper end - entity tracking events
 
     public float rotate(Rotation rotation) {
         float f = Mth.wrapDegrees(this.getYRot());
@@ -3335,7 +4172,7 @@
     }
 
     @Nullable
-    public LivingEntity getControllingPassenger() {
+    public net.minecraft.world.entity.LivingEntity getControllingPassenger() {
         return null;
     }
 
@@ -3373,20 +4210,34 @@
     }
 
     private Stream<Entity> getIndirectPassengersStream() {
+        if (this.passengers.isEmpty()) { return Stream.of(); } // Paper - Optimize indirect passenger iteration
         return this.passengers.stream().flatMap(Entity::getSelfAndPassengers);
     }
 
     @Override
     public Stream<Entity> getSelfAndPassengers() {
+        if (this.passengers.isEmpty()) { return Stream.of(this); } // Paper - Optimize indirect passenger iteration
         return Stream.concat(Stream.of(this), this.getIndirectPassengersStream());
     }
 
     @Override
     public Stream<Entity> getPassengersAndSelf() {
+        if (this.passengers.isEmpty()) { return Stream.of(this); } // Paper - Optimize indirect passenger iteration
         return Stream.concat(this.passengers.stream().flatMap(Entity::getPassengersAndSelf), Stream.of(this));
     }
 
     public Iterable<Entity> getIndirectPassengers() {
+        // Paper start - Optimize indirect passenger iteration
+        if (this.passengers.isEmpty()) { return ImmutableList.of(); }
+        ImmutableList.Builder<Entity> indirectPassengers = ImmutableList.builder();
+        for (Entity passenger : this.passengers) {
+            indirectPassengers.add(passenger);
+            indirectPassengers.addAll(passenger.getIndirectPassengers());
+        }
+        return indirectPassengers.build();
+    }
+    private Iterable<Entity> getIndirectPassengers_old() {
+        // Paper end - Optimize indirect passenger iteration
         return () -> {
             return this.getIndirectPassengersStream().iterator();
         };
@@ -3399,6 +4250,7 @@
     }
 
     public boolean hasExactlyOnePlayerPassenger() {
+        if (this.passengers.isEmpty()) { return false; } // Paper - Optimize indirect passenger iteration
         return this.countPlayerPassengers() == 1;
     }
 
@@ -3435,7 +4287,7 @@
     }
 
     public boolean isControlledByLocalInstance() {
-        LivingEntity entityliving = this.getControllingPassenger();
+        net.minecraft.world.entity.LivingEntity entityliving = this.getControllingPassenger();
 
         if (entityliving instanceof Player entityhuman) {
             return entityhuman.isLocalPlayer();
@@ -3445,7 +4297,7 @@
     }
 
     public boolean isControlledByClient() {
-        LivingEntity entityliving = this.getControllingPassenger();
+        net.minecraft.world.entity.LivingEntity entityliving = this.getControllingPassenger();
 
         return entityliving != null && entityliving.isControlledByClient();
     }
@@ -3463,7 +4315,7 @@
         return new Vec3((double) f1 * d2 / (double) f3, 0.0D, (double) f2 * d2 / (double) f3);
     }
 
-    public Vec3 getDismountLocationForPassenger(LivingEntity passenger) {
+    public Vec3 getDismountLocationForPassenger(net.minecraft.world.entity.LivingEntity passenger) {
         return new Vec3(this.getX(), this.getBoundingBox().maxY, this.getZ());
     }
 
@@ -3489,8 +4341,37 @@
         return 1;
     }
 
+    // CraftBukkit start
+    private final CommandSource commandSource = new CommandSource() {
+
+        @Override
+        public void sendSystemMessage(Component message) {
+        }
+
+        @Override
+        public CommandSender getBukkitSender(CommandSourceStack wrapper) {
+            return Entity.this.getBukkitEntity();
+        }
+
+        @Override
+        public boolean acceptsSuccess() {
+            return ((ServerLevel) Entity.this.level()).getGameRules().getBoolean(GameRules.RULE_SENDCOMMANDFEEDBACK);
+        }
+
+        @Override
+        public boolean acceptsFailure() {
+            return true;
+        }
+
+        @Override
+        public boolean shouldInformAdmins() {
+            return true;
+        }
+    };
+    // CraftBukkit end
+
     public CommandSourceStack createCommandSourceStackForNameResolution(ServerLevel world) {
-        return new CommandSourceStack(CommandSource.NULL, this.position(), this.getRotationVector(), world, 0, this.getName().getString(), this.getDisplayName(), world.getServer(), this);
+        return new CommandSourceStack(this.commandSource, this.position(), this.getRotationVector(), world, 0, this.getName().getString(), this.getDisplayName(), world.getServer(), this); // CraftBukkit
     }
 
     public void lookAt(EntityAnchorArgument.Anchor anchorPoint, Vec3 target) {
@@ -3551,6 +4432,11 @@
                                     vec3d = vec3d.add(vec3d1);
                                     ++k1;
                                 }
+                                // CraftBukkit start - store last lava contact location
+                                if (tag == FluidTags.LAVA) {
+                                    this.lastLavaContact = blockposition_mutableblockposition.immutable();
+                                }
+                                // CraftBukkit end
                             }
                         }
                     }
@@ -3613,7 +4499,7 @@
         return new ClientboundAddEntityPacket(this, entityTrackerEntry);
     }
 
-    public EntityDimensions getDimensions(Pose pose) {
+    public EntityDimensions getDimensions(net.minecraft.world.entity.Pose pose) {
         return this.type.getDimensions();
     }
 
@@ -3714,7 +4600,39 @@
         return this.getZ((2.0D * this.random.nextDouble() - 1.0D) * widthScale);
     }
 
+    // Paper start - Block invalid positions and bounding box
+    public static boolean checkPosition(Entity entity, double newX, double newY, double newZ) {
+        if (Double.isFinite(newX) && Double.isFinite(newY) && Double.isFinite(newZ)) {
+            return true;
+        }
+
+        String entityInfo;
+        try {
+            entityInfo = entity.toString();
+        } catch (Exception ex) {
+            entityInfo = "[Entity info unavailable] ";
+        }
+        LOGGER.error("New entity position is invalid! Tried to set invalid position ({},{},{}) for entity {} located at {}, entity info: {}", newX, newY, newZ, entity.getClass().getName(), entity.position, entityInfo, new Throwable());
+        return false;
+    }
     public final void setPosRaw(double x, double y, double z) {
+        this.setPosRaw(x, y, z, false);
+    }
+    public final void setPosRaw(double x, double y, double z, boolean forceBoundingBoxUpdate) {
+        if (!checkPosition(this, x, y, z)) {
+            return;
+        }
+        // Paper end - Block invalid positions and bounding box
+        // Paper start - Fix MC-4
+        if (this instanceof ItemEntity) {
+            if (io.papermc.paper.configuration.GlobalConfiguration.get().misc.fixEntityPositionDesync) {
+                // encode/decode from ClientboundMoveEntityPacket
+                x = Mth.lfloor(x * 4096.0) * (1 / 4096.0);
+                y = Mth.lfloor(y * 4096.0) * (1 / 4096.0);
+                z = Mth.lfloor(z * 4096.0) * (1 / 4096.0);
+            }
+        }
+        // Paper end - Fix MC-4
         if (this.position.x != x || this.position.y != y || this.position.z != z) {
             this.position = new Vec3(x, y, z);
             int i = Mth.floor(x);
@@ -3732,6 +4650,12 @@
             this.levelCallback.onMove();
         }
 
+        // Paper start - Block invalid positions and bounding box; don't allow desync of pos and AABB
+        // hanging has its own special logic
+        if (!(this instanceof net.minecraft.world.entity.decoration.HangingEntity) && (forceBoundingBoxUpdate || this.position.x != x || this.position.y != y || this.position.z != z)) {
+            this.setBoundingBox(this.makeBoundingBox());
+        }
+        // Paper end - Block invalid positions and bounding box
     }
 
     public void checkDespawn() {}
@@ -3818,8 +4742,17 @@
 
     @Override
     public final void setRemoved(Entity.RemovalReason reason) {
+        // CraftBukkit start - add Bukkit remove cause
+        this.setRemoved(reason, null);
+    }
+
+    @Override
+    public final void setRemoved(Entity.RemovalReason entity_removalreason, EntityRemoveEvent.Cause cause) {
+        CraftEventFactory.callEntityRemoveEvent(this, cause);
+        // CraftBukkit end
+        final boolean alreadyRemoved = this.removalReason != null; // Paper - Folia schedulers
         if (this.removalReason == null) {
-            this.removalReason = reason;
+            this.removalReason = entity_removalreason;
         }
 
         if (this.removalReason.shouldDestroy()) {
@@ -3827,14 +4760,30 @@
         }
 
         this.getPassengers().forEach(Entity::stopRiding);
-        this.levelCallback.onRemove(reason);
-        this.onRemoval(reason);
+        this.levelCallback.onRemove(entity_removalreason);
+        this.onRemoval(entity_removalreason);
+        // Paper start - Folia schedulers
+        if (!(this instanceof ServerPlayer) && entity_removalreason != RemovalReason.CHANGED_DIMENSION && !alreadyRemoved) {
+            // Players need to be special cased, because they are regularly removed from the world
+            this.retireScheduler();
+        }
+        // Paper end - Folia schedulers
     }
 
     public void unsetRemoved() {
         this.removalReason = null;
     }
 
+    // Paper start - Folia schedulers
+    /**
+     * Invoked only when the entity is truly removed from the server, never to be added to any world.
+     */
+    public final void retireScheduler() {
+        // we need to force create the bukkit entity so that the scheduler can be retired...
+        this.getBukkitEntity().taskScheduler.retire();
+    }
+    // Paper end - Folia schedulers
+
     @Override
     public void setLevelCallback(EntityInLevelCallback changeListener) {
         this.levelCallback = changeListener;
@@ -3887,7 +4836,7 @@
     }
 
     public Vec3 getKnownMovement() {
-        LivingEntity entityliving = this.getControllingPassenger();
+        net.minecraft.world.entity.LivingEntity entityliving = this.getControllingPassenger();
 
         if (entityliving instanceof Player entityhuman) {
             if (this.isAlive()) {
@@ -3962,4 +4911,14 @@
 
         void accept(Entity entity, double x, double y, double z);
     }
+
+    // Paper start - Expose entity id counter
+    public static int nextEntityId() {
+        return ENTITY_COUNTER.incrementAndGet();
+    }
+
+    public boolean isTicking() {
+        return ((net.minecraft.server.level.ServerLevel) this.level).isPositionEntityTicking(this.blockPosition());
+    }
+    // Paper end - Expose entity id counter
 }