Iron Golems can spawn naturally in villages, or be built with blocks, similar to a Snow Golem. It takes 4 Blocks of Iron to build an Iron Golem, which is equivalent to 36 Iron Ingots.
Iron Golems always spawn facing south.
Behavior
Iron Golems slowly and passively roam villages. When provoked, Iron Golems will move faster toward their target and swing their arms violently at their target (their damage ranges from 4 hearts to 10 hearts).
They will attack Endermen, zombie pigmen, blazes, silverfish, skeletons, spiders, cave spiders and zombies if any of them are within its sight. They will also attack the player if the player attacks them first or if the player attacks a nearby villager. The Iron Golem does not have to see the player attack a villager but if a player does and later moves into the Golem's line of sight then the Golem will attack the player. They do not despawn if switched to peaceful and will continue to attack the player.
Golems do not attack creepers (maybe because they would explode when it attacks them, destroying the village over time) or slimes/magma cubes (Bug?) If an Iron Golem accidentally hits another Iron Golem, it does not damage it, nor does it provoke the other Iron Golem to attack it.
Upon death, Iron Golems drop three to five Iron ingots, and sometimes one or two roses. If an Iron Golem is killed that belonged to a village, it will eventually respawn.
Iron Golems take damage from lava, fire and drowning. They do not take fall damage.
Iron Golems will sometimes pick up roses and offer them to villagers.
Uses
Defense
An Iron Golem's primary purpose is to defend villages from zombie attacks. When attacking, they swing their arms as if tossing the enemy. The enemies are thrown up into the air and killed, usually in one or two hits.
Farming
Due to the fact that Iron Golems can spawn endlessly in a village, one can kill them for their iron, and then just wait for another one to spawn. The only problem with this is that Iron Golems take an extremely long time to kill due to their large health, so you should probably prepare a couple extra swords. Another good tactic is to lure an iron golem into a 3 blocks deep water pit, so he will drown eventually being unable to stay afloat.
History
Iron Golems were introduced in 12w08a.
Gallery
An Iron Golem attacking the player.
Village Guard Holding Rose.png
An Iron Golem holding a rose.
Villager golem.jpg
An Iron Golem in a village.
An Iron Golem that hold a Rose for some Villager children in a Superflat world. (Another Iron Golem can be seen in the background, on the right, also holding a Rose.)
An Iron Golem killed a Spider and tossed it into the air.
There is no Spawn Egg for iron golem because they can be created by the player.
Since Iron Golems look like Villagers and respawn in NPC Villages, they must be created by Villagers to defend themselves against hostile mobs and particularly Zombies.
Unlike other mobs, Iron Golems sink to the bottom in lakes, rivers and oceans.
When created a snow particle effect will be displayed.
There is no maximum amount of Iron Golems per village.
Iron Golems are a renewable source of iron (only village ones).
Iron Golems are the second utility mob in Minecraft, after Snow Golems.