Sherlock is going to be a big gnarly spider. All dungeons have them, so he'll be taking on this noble burden. I haven't decided if he should be a spider-taur or just a big old offspring of Shelob and Aragog, either way he's going to be pretty big and pretty gnarly.

His function is jump scaring the users, he drops down out of holes in the ceiling and tries to capture them with his webs or bite them and inject them with venom.

He'll definitely get killed and drop a ton of loot, probably letting all the other users want to kill him more. Considering how reckless he is he'll probably lose his third life before the game is over, for a dash of angst.