The Skull Ghost is a criminal dressed as a skull-headed phantom who once tried to steal the fortune of Shaggy's uncle. He was ultimately unmasked and sent to jail by Scooby-Doo and the Boo Brothers. The Transylvanian monsters later managed to create a real version of the skull-ghost to serve in their armies of darkness. while he was only brifly mentioned in Spongebob and Friends find the black cauldron, and possably took part in it, The skull ghost has not appeared in that project, due to character amount or simply over-shadowed by more familier faverites, or due to story. but he will soon antagonize Spongebob and his friends in films to come.