Age of Worms: The Return
These strange green worms bore into the bodies of humanoids, but from there it is unclear what happens. According to Filge, these green worms come from creatures called the Spawn of Kyuss, which are incredibly tough undead creatures. Once one of the green worms gets inside a person it can transform them into an undead creature in under a day. Several of these worms have been spotted so far; Balabar Smenk stole one from the Dourstone Mine, which he then gave to Filge for study; many of these worms were seen in the Dourstone Mine itself and it seems that they were responsible for the death of Grallak Kur and his minions; most recently, one of the lizardfolk in the lair of the Twisted Branch Tribe seemed to have been infected with them as well.