He is a muscular Caucasian male with shoulder length dusty brown hair.
He claimed to be happy that he was about to retire, but it was an act.
Big Top Scooby-Doo!
He conspired with Archambault to carry out jewel robberies, using werewolf-disguised baboons. Each time he kidnapped someone from the circus he dressed another baboon in a werewolf costume and their clothes to give the impression that the werewolf was converting others.
He was caught when Scooby-Doo and Shaggy Rogers realized what the "werewolves" really were and that they could be given orders to stop in Spanish. Archambault turned against him and shot Doubleday with a tranquilizer dart before he could talk too much and incriminate him. He was then taken away in an ambulance.