Giant rats that walk upright? Terrific. These abominations are actually former adventurers like yourself, who have succumbed to a terrible disease spread amongst the giant vermin overrunning the ports and villages in these lands. A singe bite from one of them will set the process in motion, so until you are cured, you may find yourself ravenous, twitchy, and sprouting hair in unexpected places. It's like puberty, except you become a literal rat at the end.