Minecraft wiki entry for Mob_grinder, associated text: It is possible to grind mobs by smashing them with an anvil. To start, the mobs should be contained in a small 1×1 chamber with an open ceiling. Next you should have a tall pillar on one wall chamber which you can climb and drop an anvil from. If dropped from a sufficient height, all mobs should be instantly slaughtered. You can then collect the drops with a hopper or just by entering the chamber. You may wish to place a torch or sign at the bottom of the chamber to break the anvil and prevent it from being damaged. It would then be possible to automatically transport the items and anvil back up to the top using some sort of vertical item transportation.