Zombie

Zombies are common, undead hostile mobs.

Spawning
In the Overworld, zombies spawn in groups of 4 at a light level of 7 or less. Zombies have a 5% chance to spawn as a zombie villager and a 5% chance to spawn as a baby zombie. Baby zombies have an additional 5% chance of spawning as a chicken jockey. This also applies to spawn eggs.

Sieges
If a player is in a village with at least 10 doors and 20 villagers at midnight, up to 20 zombies may be spawned near the edge of the village regardless of light level or transparent blocks. It can happen in any biome, even if it is Mushroom Island.

Monster spawners
Zombies can spawn from monster spawners inside dungeons.

Zombie villagers
Zombie villagers comprise 5% of all spawned zombies. They behave as ordinary zombies, but their character model's head and face is reminiscent of that of a villager, shaded with a darker green hue. Zombie villagers retain their professions and clothes, which have a tattered appearance (except in the Console Edition).

Zombie villagers can also result from zombie attacks on villagers. If any type of zombie kills a villager, there is a chance that the villager will transform into a zombie villager (100% on hard difficulty, 50% on normal, 0% on easy).

Zombie villagers can be cured by a golden apple on them while they are under the effects of Weakness, which can be applied using a splash potion of Weakness thrown by the player or a witch. A loud hissing sound will be heard if successful, and the zombie villager will begin to shudder. The curing process will take 2–5 minutes, during which time the zombie villager behaves as normal. While the zombie is being cured, it will have the strength I effect in normal difficulty (or strength II on hard difficulty), making it more important to isolate and restrain the zombie.


 * Cured villagers do not retain any trades they had before they became infected. Additionally in the Console Edition, zombie villagers that are cured are given professions at random.
 * If the zombie villager is wearing any armor or wielding tools or weapons, those items disappear when the villager is cured.
 * During the curing process, it is often a good idea to keep the zombie villager away from any other zombies, because the other zombies will attack it after it is cured.
 * Conversion can be sped up by around 4% by surrounding the zombie villager with iron bars and/or bed blocks within a 9×9×9 cube centered on the zombie villager.

A zombie villager cannot be cured by switching from Easy, Normal or Hard difficulty to Peaceful; they will simply despawn like all other monsters.

Baby zombies
Baby zombies make up 5% of zombie spawns. They behave similar to regular zombies, with the following oddities:
 * They do not burn in sunlight.
 * They are faster than the normal zombie, yet they have the same HP as normal zombies. This makes the baby zombie more dangerous than their bigger "cousins".
 * The noises they make are higher-pitched than normal zombie sound effects.
 * They can sometimes ride chickens.
 * Baby zombie villagers will turn into baby villagers if cured.
 * Worn armor shrinks to fit their body size.
 * They are able to fit through 1×1 block gaps.
 * They give more Experience Orbs when killed by the player.

Baby zombie villagers are spawned when a zombie kills a baby villager, the chance of infection being the same as adult zombie villagers. Baby zombie villagers also spawn naturally, but the combined chance (5% villagers × 5% babies) is very low at 0.25% of all newly spawned zombies.

Armed zombies
Along with skeletons, some spawned zombies can pick up dropped items from the ground. These zombies will automatically hold any item they come across (except that jack o'lanterns, mob heads, and pumpkins will be worn on their heads), but if those items happen to be armor, weapons, or tools, the zombie will use them. If they encounter another similar item, they will pick it up and drop their previous item:


 * if the new item is armor or a weapon and the old item was not (for example, zombies prefer swords to pickaxes, and helmets to pumpkins),
 * if the new item is a higher tier material (from least to best: wooden or leather, gold, chain, iron, diamond),
 * if both items are the same material, the new item is enchanted, and the old is not, or
 * if both items are the same material and the new item is more damaged than the old item.

Items dropped by zombies in exchange for another cannot be picked up by them again until 10 game ticks has passed (0.5 seconds, barring lag), but can be picked up by hoppers and other entities (other zombies, skeletons, players).

Armor worn by zombies is not damaged from most damage sources, which means it cannot "wear out" the way player armor does. Helmets (not blocks like pumpkins) on zombies can wear away and break if the zombie is exposed to daylight or has an anvil or other falling block dropped on its head. Zombies also have a natural armor rating of, which gives 8% damage reduction from most sources.

Some zombies which can pick up items spawn already in possession of such items, and those items may also be enchanted. The chances of that event are listed below. Zombie villagers can also spawn naturally with armor, weapons or tools. If a zombie spawns wearing multiple pieces of armor, the armor will never be mismatched (i.e. all pieces will be made of the same material).

If a zombie does spawn with armor, the chances of specific armor are as follows:

The chances of it being of a particular material are:

Any zombie that spawns with equipment (picked-up items don't count) will give 1-3 extra experience points per item.

Drops
When killed, zombies drop 0-2 pieces of rotten flesh.

Zombies will rarely drop iron ingots, carrots, potatoes, and any naturally spawned equipment. Any picked-up equipment has 100% chance of dropping and will drop with the same damage level it had when picked up, while any naturally spawned equipment has a 8.5% (9.5% with Looting I, 10.5% with Looting II and 11.5% with Looting III) chance of dropping and will drop with a random durability.

A zombie will drop its head if killed by a charged creeper's explosion.

Zombies drop 5 experience when killed by a player or tamed wolf, and an extra 1-3 experience if the zombie has equipment. If the zombie is a baby, it will drop an additional 7 experience.

Halloween
If a zombie wearing a pumpkin or jack o'lantern is killed using a tool enchanted with Looting, there will be a chance equivalent to the level of Looting used to drop the pumpkin or jack o'lantern, up to a maximum of a 3% chance of a drop.

Behavior


Zombies spawn in groups of 4 and will pursue the player on sight from 40 blocks away, as opposed to 16 blocks in other hostile mobs. The detection range of zombies is reduced to half of their normal range (20 blocks) when the player is wearing a zombie mob head (except in the Console or Pocket Editions). Zombies will attempt to avoid obstacles, including sheer cliffs and lava, and will try to find the shortest path towards the player. Unlike skeletons, zombies do not try to avoid being hit, and continue to pursue the player even when being attacked. Zombies can sometimes deal damage through a closed door, as shown on the picture to the right. Like most mobs, zombies will always float on water, even if their target is below them.

At dawn, generally when the sun is 15 degrees or more above the ground (that is, when the moon can no longer be seen), most zombies will catch fire and burn once exposed to direct sunlight, except if they are caught in cobwebs. Zombies with head armor are immune to sunlight, but the armor piece will take damage. They may make some attempt to seek out shade during this time, or enter bodies of water to protect themselves from burning up, but will exit protective areas to chase a nearby player or villager. If they attack an entity while burning, they may set it on fire, causing additional damage. If wearing armor enchanted with Thorns while burning they may set players attacking them on fire with thorns damage alone.

As zombies are undead mobs, they are harmed by the status effect Healing and healed by the status effect Harming. They are also unaffected by regeneration and poison.

A zombie holding an item given by a player will not despawn when left alone.

Attacking villagers
Zombies will attack villagers within 42 blocks, and they can always see villagers through walls. Once a zombie has focused on a villager, the zombie will ignore any other villagers and the player, until its target is dead or a mob or player attacks the Zombie. Escaping villagers may even run into a fire to "escape" from zombies.

Zombies will bang on closed wooden doors, and on Hard (and Hardcore) difficulty, up to 14.5% of them (depending on regional difficulty) can succeed in breaking them down. Otherwise, the door will crack, but not break. Iron doors are always safe.

Attacking iron golems
Zombies will attack iron golems within 42 blocks.

Reinforcements
On Hard difficulty, zombies can spawn additional zombies to “help” when damaged. Each zombie has a "likeliness to call reinforcements" statistic which ranges from 0–10%, and "leader" zombies (0–5% depending on regional difficulty) get a bonus of 50–75 percentage points to the stat. When the zombie is damaged by an entity or is damaged while targeting an entity, up to 50 attempts will be made to randomly choose a spawn location (0 or ±7–40 blocks away in all three axes) that is above a block with a solid top surface, has light level 9 or lower, has no players within 7 blocks, and has no colliding entities or blocks at which to spawn the reinforcement. Both the damaged zombie and the new zombie will have a 5 percentage point penalty to their "likeliness to call reinforcement" stat, making it less likely that an infinite number of zombies will spawn.

On all difficulty levels, damaged zombies will also call all other zombies within a 67×67×21 to 111×111×21 area centered on the attacked zombie to target the attacking player, like zombie pigmen.

These effects can be negated by killing the zombie in as few hits as possible, by using environmental damage such as cactus or lava, or by avoiding them completely.

Data values
Zombies have entity data associated with them that contain various properties of the mob. Their entity ID is.