Skull Ghost

The Skull Ghost is a scriminal dressed as a skull-headed phantom who onced 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. The skull ghost has not appeared yet, but he will soon antagonize Spongebob and his friends in films to come.