(NOTE: Before reading the details on this bug below, note what Jon Kågström, the person who first created Iron Golems, said here: https://twitter.com/jonkagstrom/status/175289055314059264 )
This bug affects all versions ever released, beginning at about MineCraft 1.2.
The day I discovered this bug, I was playing on Survival mode on (I think) Minecraft 1.2, and I finally acquired the resources needed to build two Iron Golems. I decided to build them in an NPC Village I found (there WEREN'T enough Villagers and houses for Iron Golems to spawn naturally), so as to help defend the Village. (For some reason, Iron Golems would just stand around and do nothing if I didn't create them nearby one or more Villagers.) At some point later, I exited my world so I could do something else.
Later, I came back to world to play some more on it. While killing mobs for loot (I did this close to the Village so that the Iron Golems could provide me additional defense), a Villager ran right in front of my line of sight, so that I wound up accidentally hitting him. Next thing I know, my Iron Golems end up attacking me, trying to kill me. |=(
This bug occurs also on Creative and Hardcore mode, as well as Survival mode.
How to Reproduce:
1) Build an Iron Golem in a Village (it can be either natural OR artificial, as I've also witnessed the bug occur in villages I built; preferably the Iron Golem should be built close to at least 1 Villager); if done correctly, the Iron Golem will proceed to behave like an Iron Golem that spawned naturally in the Village.
2) Exit the world, then return to it (length of time between exiting and reentering the world doesn't matter).
3) Do something that would provoke a naturally-spawned Iron Golem into attacking you (i.e.: Killing a Baby Villager); preferably nearby it.
4) The Iron Golem YOU (the Player) made should attempt to attack you.
(Note: I've started to notice that, at some point before the 1.4 release (I can't remember exactly when), ONLY on Creative mode, the likelihood/frequency at which an Iron Golem(s) I made would try to attack me after being provoked by me, gradually began to lessen; by the time 12w49a was released, this bug would no longer occur (in Creative mode). It still occurs as normal in Survival and Hardcore mode.)
Comments 3
Through rigorous and extensive testing of this bug, I found that, under certain strenuous conditions—the kind that could lag MineCraft to the point of crashing/freezing indefinitely (i.e.: approx. 100 Villagers and Baby Villagers being chased by about 200+ item-wielding Zombies, Villager Zombies, and Baby Villager Zombies, being in turn chased by 6-8 Iron Golems, all under the influence of Extended Speed I and II, Extended Strength I and II, Extended Regeneration I, Extended Slowness I, and other similar potion effects)—the Iron Golem bug could still occur. (Unfortunately, I couldn't reproduce the bug in that same method a second time for the purpose of taking a screenshot of it.)
I was unable to replicate this bug in 1.4.5 and the latest snapshot 12w50a. I loaded into a new superflat world and built a few iron golems. I than exited the world, reentered, and went on a rampage, killing every villager near them. They did nothing. I then attacked the golems themselves and they didn't even fight back - they just stood around passively while I slaughtered them.