This is a note found as a random drop from breakable bookshelves.
The resulting abomination bore the torso of a man and tail of a snake, with a reptilian snout unlike either species. Its eyes stared back at you with a hint of human sorrow, though it was clearly a dulled mind with no indication that the original person was present within. It slithered around with surprising agility when food was placed within the confines of its cage. Evidently, the late Arcanist Hargate considered this experiment a success, calling it a Slith in his notes. It was not long before the Slith turned on its creator during feeding, tearing the arcanist limb from limb.
None can say for sure what happened next, but the Slith must have escaped into the sewer systems, and eventually out into the wild...