Minecraft wiki entry for Iron_Golem, associated text: As with all utility mobs, iron golems can be leashed. The leashed iron golem does not try to break from the lead when it sees a hostile mob. Instead, it looks at the mob while moving. An iron golem that is leashed in mid-air moves its arms and legs while moving. If an iron golem is leashed to a fence, it attacks the hostile mob but does not follow the mob if the hostile mob goes out the attack range, as the iron golem cannot break free from fence leads.