Tuthul in Soljund's Sinkhole was given dead body cleanup script in USKP v1.0, but this change was reverted in v1.3.1. With that update, some of the NPCs had their script removed because they're living far away from a population center. However, Soljund's Sinkhole, for all intents and purposes, is a population center. I imagine that this error was made because it is marked as a cave in vanilla. In addition, Tuthul's boss Perth still has the script.