papermc/paper-server/nms-patches/net/minecraft/world/entity/EntityCreature.patch

--- a/net/minecraft/world/entity/EntityCreature.java
+++ b/net/minecraft/world/entity/EntityCreature.java
@@ -7,6 +7,10 @@
 import net.minecraft.world.level.World;
 import net.minecraft.world.phys.Vec3D;
 
+// CraftBukkit start
+import org.bukkit.event.entity.EntityUnleashEvent;
+// CraftBukkit end
+
 public abstract class EntityCreature extends EntityInsentient {
 
     protected EntityCreature(EntityTypes<? extends EntityCreature> entitytypes, World world) {
@@ -41,6 +45,7 @@
 
             if (this instanceof EntityTameableAnimal && ((EntityTameableAnimal) this).isSitting()) {
                 if (f > 10.0F) {
+                    this.level.getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), EntityUnleashEvent.UnleashReason.DISTANCE)); // CraftBukkit
                     this.unleash(true, true);
                 }
 
@@ -49,6 +54,7 @@
 
             this.y(f);
             if (f > 10.0F) {
+                this.level.getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), EntityUnleashEvent.UnleashReason.DISTANCE)); // CraftBukkit
                 this.unleash(true, true);
                 this.goalSelector.a(PathfinderGoal.Type.MOVE);
             } else if (f > 6.0F) {