--- a/net/minecraft/world/entity/monster/EntityZombie.java
+++ b/net/minecraft/world/entity/monster/EntityZombie.java
@@ -66,6 +66,15 @@
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.state.IBlockData;
 
+// CraftBukkit start
+import net.minecraft.server.MinecraftServer;
+import org.bukkit.entity.Zombie;
+import org.bukkit.event.entity.CreatureSpawnEvent;
+import org.bukkit.event.entity.EntityCombustByEntityEvent;
+import org.bukkit.event.entity.EntityTargetEvent;
+import org.bukkit.event.entity.EntityTransformEvent;
+// CraftBukkit end
+
 public class EntityZombie extends EntityMonster {
 
     private static final UUID SPEED_MODIFIER_BABY_UUID = UUID.fromString("B9766B59-9566-4402-BC1F-2EE2A276D836");
@@ -86,6 +95,7 @@
     private boolean canBreakDoors;
     private int inWaterTime;
     public int conversionTime;
+    private int lastTick = MinecraftServer.currentTick; // CraftBukkit - add field
 
     public EntityZombie(EntityTypes<? extends EntityZombie> entitytypes, World world) {
         super(entitytypes, world);
@@ -202,7 +212,10 @@
     public void tick() {
         if (!this.level().isClientSide && this.isAlive() && !this.isNoAi()) {
             if (this.isUnderWaterConverting()) {
-                --this.conversionTime;
+                // CraftBukkit start - Use wall time instead of ticks for conversion
+                int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
+                this.conversionTime -= elapsedTicks;
+                // CraftBukkit end
                 if (this.conversionTime < 0) {
                     this.doUnderWaterConversion();
                 }
@@ -219,6 +232,7 @@
         }
 
         super.tick();
+        this.lastTick = MinecraftServer.currentTick; // CraftBukkit
     }
 
     @Override
@@ -251,6 +265,7 @@
     }
 
     public void startUnderWaterConversion(int i) {
+        this.lastTick = MinecraftServer.currentTick; // CraftBukkit
         this.conversionTime = i;
         this.getEntityData().set(EntityZombie.DATA_DROWNED_CONVERSION_ID, true);
     }
@@ -264,11 +279,15 @@
     }
 
     protected void convertToZombieType(EntityTypes<? extends EntityZombie> entitytypes) {
-        EntityZombie entityzombie = (EntityZombie) this.convertTo(entitytypes, true);
+        EntityZombie entityzombie = (EntityZombie) this.convertTo(entitytypes, true, EntityTransformEvent.TransformReason.DROWNED, CreatureSpawnEvent.SpawnReason.DROWNED);
 
         if (entityzombie != null) {
             entityzombie.handleAttributes(entityzombie.level().getCurrentDifficultyAt(entityzombie.blockPosition()).getSpecialMultiplier());
             entityzombie.setCanBreakDoors(entityzombie.supportsBreakDoorGoal() && this.canBreakDoors());
+            // CraftBukkit start - SPIGOT-5208: End conversion to stop event spam
+        } else {
+            ((Zombie) getBukkitEntity()).setConversionTime(-1);
+            // CraftBukkit end
         }
 
     }
@@ -308,9 +327,9 @@
                     if (SpawnerCreature.isSpawnPositionOk(entitypositiontypes_surface, this.level(), blockposition, entitytypes) && EntityPositionTypes.checkSpawnRules(entitytypes, worldserver, EnumMobSpawn.REINFORCEMENT, blockposition, this.level().random)) {
                         entityzombie.setPos((double) i1, (double) j1, (double) k1);
                         if (!this.level().hasNearbyAlivePlayer((double) i1, (double) j1, (double) k1, 7.0D) && this.level().isUnobstructed(entityzombie) && this.level().noCollision((Entity) entityzombie) && !this.level().containsAnyLiquid(entityzombie.getBoundingBox())) {
-                            entityzombie.setTarget(entityliving);
+                            entityzombie.setTarget(entityliving, EntityTargetEvent.TargetReason.REINFORCEMENT_TARGET, true); // CraftBukkit
                             entityzombie.finalizeSpawn(worldserver, this.level().getCurrentDifficultyAt(entityzombie.blockPosition()), EnumMobSpawn.REINFORCEMENT, (GroupDataEntity) null, (NBTTagCompound) null);
-                            worldserver.addFreshEntityWithPassengers(entityzombie);
+                            worldserver.addFreshEntityWithPassengers(entityzombie, CreatureSpawnEvent.SpawnReason.REINFORCEMENTS); // CraftBukkit
                             this.getAttribute(GenericAttributes.SPAWN_REINFORCEMENTS_CHANCE).addPermanentModifier(new AttributeModifier("Zombie reinforcement caller charge", -0.05000000074505806D, AttributeModifier.Operation.ADDITION));
                             entityzombie.getAttribute(GenericAttributes.SPAWN_REINFORCEMENTS_CHANCE).addPermanentModifier(new AttributeModifier("Zombie reinforcement callee charge", -0.05000000074505806D, AttributeModifier.Operation.ADDITION));
                             break;
@@ -331,7 +350,14 @@
             float f = this.level().getCurrentDifficultyAt(this.blockPosition()).getEffectiveDifficulty();
 
             if (this.getMainHandItem().isEmpty() && this.isOnFire() && this.random.nextFloat() < f * 0.3F) {
-                entity.setSecondsOnFire(2 * (int) f);
+                // CraftBukkit start
+                EntityCombustByEntityEvent event = new EntityCombustByEntityEvent(this.getBukkitEntity(), entity.getBukkitEntity(), 2 * (int) f); // PAIL: fixme
+                this.level().getCraftServer().getPluginManager().callEvent(event);
+
+                if (!event.isCancelled()) {
+                    entity.setSecondsOnFire(event.getDuration(), false);
+                }
+                // CraftBukkit end
             }
         }
 
@@ -413,8 +439,17 @@
             if (worldserver.getDifficulty() != EnumDifficulty.HARD && this.random.nextBoolean()) {
                 return flag;
             }
+            // CraftBukkit start
+            flag = zombifyVillager(worldserver, entityvillager, this.blockPosition(), this.isSilent(), CreatureSpawnEvent.SpawnReason.INFECTION) == null;
+        }
 
-            EntityZombieVillager entityzombievillager = (EntityZombieVillager) entityvillager.convertTo(EntityTypes.ZOMBIE_VILLAGER, false);
+        return flag;
+    }
+
+    public static EntityZombieVillager zombifyVillager(WorldServer worldserver, EntityVillager entityvillager, net.minecraft.core.BlockPosition blockPosition, boolean silent, CreatureSpawnEvent.SpawnReason spawnReason) {
+        {
+            EntityZombieVillager entityzombievillager = (EntityZombieVillager) entityvillager.convertTo(EntityTypes.ZOMBIE_VILLAGER, false, EntityTransformEvent.TransformReason.INFECTION, spawnReason);
+            // CraftBukkit end
 
             if (entityzombievillager != null) {
                 entityzombievillager.finalizeSpawn(worldserver, worldserver.getCurrentDifficultyAt(entityzombievillager.blockPosition()), EnumMobSpawn.CONVERSION, new EntityZombie.GroupDataZombie(false, true), (NBTTagCompound) null);
@@ -422,15 +457,17 @@
                 entityzombievillager.setGossips((NBTBase) entityvillager.getGossips().store(DynamicOpsNBT.INSTANCE));
                 entityzombievillager.setTradeOffers(entityvillager.getOffers().createTag());
                 entityzombievillager.setVillagerXp(entityvillager.getVillagerXp());
-                if (!this.isSilent()) {
-                    worldserver.levelEvent((EntityHuman) null, 1026, this.blockPosition(), 0);
+                // CraftBukkit start
+                if (!silent) {
+                    worldserver.levelEvent((EntityHuman) null, 1026, blockPosition, 0);
                 }
 
-                flag = false;
+                // flag = false;
             }
-        }
 
-        return flag;
+            return entityzombievillager;
+        }
+        // CraftBukkit end
     }
 
     @Override
@@ -483,7 +520,7 @@
                             entitychicken1.finalizeSpawn(worldaccess, difficultydamagescaler, EnumMobSpawn.JOCKEY, (GroupDataEntity) null, (NBTTagCompound) null);
                             entitychicken1.setChickenJockey(true);
                             this.startRiding(entitychicken1);
-                            worldaccess.addFreshEntity(entitychicken1);
+                            worldaccess.addFreshEntity(entitychicken1, CreatureSpawnEvent.SpawnReason.MOUNT); // CraftBukkit
                         }
                     }
                 }
