Talk:The Underworld/@comment-15695624-20150716232725

Another new thing is that mobs in the Underworld have a chance of dropping the top tier pre-Hardmode Yo-yo, the Cascade, after Skeletron is defeated. I'm not sure what the drop rate is - it might be pretty rare. I spent several hours over 3 play sessions running the length of my Hellbridge in one of my large worlds, and finally one drops from a Hellbat.

The Underworld is also where you can find the Tax Collector NPC. He spawns as the Tortured Soul after entering Hardmode and is initially hostile. Throwing Purification Powder on him turns him into the Tax Collector.

Hell isn't so safe in Hardmode after beating a mechanical boss. Red Devils and Lava Bats start to spawn.