Guitar Ghoul “The Caveman was the disguise of Joe Grimm, the security guard of a museum. Insert details here. Caveman (Scooby-Doo! Unmasked) Pages in category "Scooby-Doo! Unmasked monsters" The following 2 pages are in this category, out of 2 total. C Caveman (Scooby-Doo! Unmasked)G Guitar Ghoul Retrieved from "http://scoobydoo.wikia.com/wiki/Category:Scooby-Doo!_Unmasked_monsters"