Minecraft wiki entry for Defeating_a_woodland_mansion, associated text: You can bring a iron golem from a village or make your own, but it is suggested that you make the iron golem yourself since if you accidently hit it it won't retaliate like the naturally spawned golem, it is also hard to move the iron golem across rivers and trees if you decide to steal one from a village, and it might die fighting hostile mobs before it got to the mansion.