The Ghost Clown is secretly portrayed by Harry The Hypnotist in "Bedlam in The Big Top". He dressed up as the Ghost Clown, and hypnotized Shaggy, Scooby, and Daphne in to doing dangerous acts in Barnstorm's circus, causing mayhem. He went against the circus because he was sent to prison after he was caught stealing at the circus. He has only made one appearance in the series.
During this he got hypnotized himself into believing he was a chimpanzee by Shaggy and Scooby-Doo using his gold coin and two mirrors while the duo keep their eyes closed.