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 spawn in NPC Villages naturally, provided the town is big enough. 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 short T-shape, and then placing a pumpkin 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 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. They can take damage from lava, fire, 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 Villager children, symbolizing the friendly relationship between Iron Golems and the Villagers.

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 do not attack Creepers, likely due to a Creepers destructive nature which may destroy sections of the village. They will attack the player if the player attacks it 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.

It is possible for Iron Golems to accidentally attack one another, although this will deal no damage nor provoke them against each other. If an Iron Golem generated as part of a NPC Village is killed, another will eventually respawn.

They are affected by every potion effect (confirmed) except strength and weakness (not confirmed), although with the weakness effect they can kill in one hit so maybe max damage is greater than 20(?).

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 on one attack. 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 using respawning ones from NPC Villages is possible.

History
Iron Golems were first introduced in Snapshot 12w08a.

Bugs

 * Iron Golems will not attack Slimes, Magma Cubes, or Ghast. They may not attack Slimes due to their overabundance on Superflat worlds.
 * Sometimes, their texture will but to either pure white or invisible.
 * 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 attacks a group of Zombie Pigmen, the whole group won't turn hostile towards the Golem, only the one attacked.
 * As of 12w08a, after attacking an Iron Golem and making it aggressive, logging out of the world then back in will make the Iron Golem peaceful again.

Trivia

 * Iron Golems holding out roses to Villager children is a reference to the robot in the Japanese anime movie Laputa: Castle in the Sky.
 * When Villager children notice the rose in its hand, they will slowly approach, and take the flower away 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, Iron Golems will sink to the bottom of any liquid.
 * Iron Golems will avoid water whenever possible.
 * When created, a snow particle effect will display.
 * There is no maximum amount of Iron Golems per village.
 * Iron Golems could be potentially used as a utility mob, the first being the snow golem
 * 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.
 * Cave Spiders can poison Iron Golems.
 * Iron golems wobble as they walk, unique to other mobs which are completely upright when walking.