Uncle Stuart is a middle-aged Caucasian male with a flat nose and gray hair, sideburns, and beard. He wears a brown suit, light blue shirt, and black necktie. He also wears black, square-shaped, thick-framed glasses. To appear older, he uses makeup and a wig to give the illusion that he has white hair and is partially balding.
He acts like he's the intended victim of the ghost of Elias Kingston, but that was just a ploy. He's also ruthless enough to steal from his own family and kidnap his own niece to cover his tracks.
Scooby-Doo, Where Are You!
Season oneWhile Mystery Inc. traveled to see their friend Sharon Wetherby they observed a man going into an old mansion. After arriving at the Wetherby Estate, Sharon told the gang about the disappearance of her Uncle Stewart, prompting them to investigate whether it was the man they saw. They found Stuart at the abandoned Kingston Mansion, but he had aged into an old man. Stuart told them that the Ghost of Elias Kingston commanded him to come to the mansion and insisted that the Wetherby fortune was rightfully his. Stuart also stated that the ghost made him into an old man and threatened to curse the other Wetherby family members with old age unless they turned over the Wetherby fortune. Later that night, Stuart was beckoned by the Ghost's voice again and the gang found that both Stuart and Sharon had gone missing. Returning to the Kingston Mansion to search for two missing Wetherbys, Shaggy eventually found the skeleton of Stuart. The Ghost appeared to the gang soon after to demand the fortune, with Stuart's skeleton serving as a warning of the curse of old age.
After finding clues at the Kingston Masoleum and a Swami shop, the gang set a trap for the the Ghost by bringing him a phony Wetherby fortune and tricking him with projection effects. Unaware that Sharon had been found and rescued from his secret room in the mansion, the Ghost retreated there to discover the skeleton of Uncle Stuart in her place. Concluding that the mansion was truly haunted, he tried to leave but was captured by the gang.
The Ghost was unmasked to reveal Uncle Stuart, who disguised himself as the Ghost and as an older version of himself in an attempt to steal the family fortune. He kidnapped Sharon when she saw his white-haired wig blow off in the wind and knew that he was faking his aged appearance. Stuart used a recording of the ghostly voice as part of his scheme and intended to use the Swami shop as part of his plan to get away. Mr. Wetherby contacted the sheriff to arrest Stuart and finish the investigation.