End or Nether — you'll need special items like obsidian or Eyes of Ender.

To make a mob farm in Minecraft that automatically spawns and kills enemies, you'll need stone, trapdoors, chests, hoppers, ...

Making an iron golem will take a good deal of effort, but the end result is a very worthy ally. With one of your own, you can leave them to watch over your own base while you're away, or have them ...