Iron Golem

Iron Golems are large, 3 block-high, strong utility mobs. Their main purpose is to defend Villagers in NPC Villages from hostile mobs.

Creation
Iron Golems will automatically spawn in NPC Villages naturally, provided there are 15 villagers. It does not even have to be a naturally generated Village; as long as there are 15 villagers and a house, an Iron Golem will spawn.

The player may create them using blocks in a similar fashion to Snow Golems. To do so, the player must place 4 blocks of iron in a T-shape, and then place a pumpkin or a Jack-O-Lantern on top. This is equivalent to 36 iron ingots, making creation somewhat of a task. They will always spawn facing south.

Behavior
Iron Golems roam in villages rather slowly. When provoked, Iron Golems will move toward their target at a faster rate, swinging their arms up violently once in range to attack. This does 3½ to 10 hearts damage to their target and flings them into the air. They can take damage from lava, fire, poison, and drowning. They do not take fall damage. Upon death, Iron Golems drop three to five iron ingots, and sometimes one or two roses.

Iron Golems are able to hold roses and give them to Villagers, symbolizing the friendly relationship between the Villagers and Iron Golems.

Iron Golems will attack all hostile and neutral mobs if any come within their sight, except Creepers, Slimes, Magma Cubes, Wolves, and Ghasts. Iron Golems likely do not attack Creepers because of Creepers' destructive nature, which may destroy sections of the village. They will attack the player if the player attacks them first, or if the player attacks a Villager (only in Survival Mode). The Iron Golem does not have to directly see the player attacking a Villager to become hostile toward the player. They do not despawn if the difficulty is switched to peaceful and will continue to attack the player.

Iron Golems have a larger than normal attack range, this causes them to be able to attack through a solid 1 block thick wall, even without line of sight to the target. If an Iron Golem generated as part of an NPC Village is killed, another will eventually spawn to take its place.

Defense
An Iron Golem's primary purpose is to defend NPC Villages from Zombie attacks. When attacking, they swing their arms as if tossing the enemy. The enemies are thrown up into the air and normally are killed in one or two attacks. Player usage might involve a large fenced off area inhabited by them to prevent wandering off, although such control of the area could be accomplished in more simple ways.

Farming
Although difficult to kill, farming iron from them making use of the automatic respawning in NPC Villages is possible. Since Iron Golems cannot swim, it is possible to lure them into a 3-block deep pool of water, where they will eventually drown.

It is possible to make a completely automatic iron farm by making a "house" for NPC villagers to spawn in at a village and have there be a pit below. When an iron golem spawns in that pit, which they always will, the player can have a trap set up to push the iron golem into some water (typically using pistons), have them drown, and have the iron ingots fall into a collection area. Furthermore, using knowledge of their spawning conditions, a player can make a trap where the iron golems spawn so rapidly that iron ingots can be produced very, very quickly.

History
Iron Golems were first introduced in Snapshot 12w08a.

Bugs

 * When creating Iron Golems in a 3 tall area (the pumpkin directly against the ceiling), the block directly above the Iron Golem will break.
 * If an Iron Golem dies in lava, the block(s) of lava that it died in will be removed and the lava will not flow into those blocks even when they are filled with another block and it is mined out again.
 * If an Iron Golem attacks a group of Zombie Pigmen, the whole group won't turn hostile towards the Golem, only the one attacked.
 * If an Iron Golem falls into a 3x3 pit of water, it will spin rapidly.
 * An Iron Golem riding a minecart will ignore everything, even if a target is in attack range.
 * Hostile mobs do not attack the Iron Golem until the Golem attacks them.
 * For some reason, an Iron Golem can swim out of a water pit in a case like this:

Trivia

 * As the population of a village increases, more Golems will naturally spawn.
 * Castleintheskyrobot.png Iron Golems holding out roses to Villager children is a reference to the ancient robots in the Japanese anime movie Laputa: Castle in the Sky, as is the fact that the Golems are covered in vines.
 * When Villager children notice the rose in its hand, they will slowly approach, and take the flower eventually.
 * As with Snow Golems, the pumpkin must be placed last.
 * Also as with Snow Golems, there is no Spawn Egg for this mob. This is because the player can create them through other means.
 * It is implied by their looks and natural generation location that these were created by Villagers to defend them.
 * Unlike other mobs (apart from the Magma Cube), Iron Golems will sink to the bottom of any liquid.
 * Iron Golems will avoid water whenever possible.
 * Iron Golems do not take damage when making contact with water (akin to the concept of iron rusting away), but still can drown in the water.
 * When created, a snow particle effect will display.
 * There is no maximum number of Iron Golems per village.
 * Despite being crafted with a pumpkin head like a Snow Golem, the Iron Golem's head is made of iron instead of being a pumpkin, possibly being covered with crafted iron.
 * Iron Golems wobble as they walk, unique to other mobs which are completely upright when walking.
 * Tamed Wolves will not be attacked by the Iron Golems if they are focused on the player.
 * Iron Golems have the second highest health points in the game, the first being the Ender Dragon boss.