Minecraft wiki entry for Mob_grinder, associated text: A campfire killer has advantages over both a lava grinder (above) and a trident killer (below). A campfire does not destroy items like lava can. A campfire can kill nearly any mobs including baby zombies that would normally fit in a space under lava. While it does not bestow experience on players like a trident killer, a campfire killer is much cheaper and simpler to construct, requiring only water, a sign, a hopper, a chest, a glass block, and a campfire. A campfire requires only wood to make the crafting ingredients. It is an excellent choice for early-game farms.