Clarence

Clarence the caretaker was the disguise of Zarko the magician, who had kidnapped Shaggy Rogers' Uncle Shagworthy.

Season one
The Clarence Mystery Inc. first met was probably a hologram, because he seemed to be dragged through the wall by the Black Knight, and Merlin was standing right there too. But Zarko was wearing a Clarence mask under his Merlin mask at the end.

Appearances

 * The Scooby-Doo Show
 * Scared a Lot in Camelot