Minecraft wiki entry for Spawner_traps, associated text: Similarly to the Iron Golem trap, have tamed wolves kill mobs for you. However, this only works for skeleton dungeons, as wolves will only automatically target skeletons. Additionally, as wolves have much less health than golems, you'll need to either have many wolves available, or weaken the skeletons beforehand (i.e. a large fall). The benefit of wolf traps over golem traps is that kills from tamed wolves can produce experience and extra loot.