Scooby-Doo, Scared a Lot in Camelot Episode aired Oct 16, 1976

“Uncle Shagworthy took a liking to an old castle in England,” explains his nephew Shaggy. “So he had it shipped over here and put back together, stone by stone.” Unfortunately, two ghosts, Merlin the sorcerer and the Black Knight, seem to have come along for the ride. After attending a performance by Zarko the magician, Scooby, Shaggy and the gang visit Uncle Shagworthy only to find that he’s vanished. Meanwhile the two ghosts try to scare them away. . . . Manyfaces, an evil master of disguise, has developed a haunting melody that immediately puts its hearers to sleep. The criminal mastermind finds a way to expose everyone in Big City to this hypnotic tune, which allows Manyfaces and his henchmen to rob everyone blind. It’s up to the Blue Falcon and his mechanical sidekick, Dynomutt the Dog Wonder, to stop him. But Manyfaces’s many faces include that of the Blue Falcon.