He is Oscar Proud's successful and lifelong arch-nemesis who made his fortune on a basketball shot that Oscar missed back in high-school; he now owns virtually the whole setting of the show. It is implied that Wizard Kelly is a pun for Magic Johnson. It is probably more accurate to say that Wizard Kelly's last name comes from the maiden name of Magic Johnson's wife, Earleatha "Cookie" Kelly. The gag on Magic Johnson's wife is extended in the fact that Wizard Kelly's wife is mentioned to be named Gingersnaps. The name of the town that the Proud Family lives in is Wizville, California, as shown when Penny gets her driver's license in The Proud Family Movie.
Despite all the mean things he's done to Oscar, he still attends all of Wizard Kelly's events.
A running gag of the series is his notoriously lousy memory; that he doesn't remember the names of the main characters, no matter how many times they tell him. He always calls Zoey "Susie" and Oscar "Oliver Prune".
The front of Wizard Kelly's face is never shown in any of the episodes. Instead, the shot is awkwardly angled so that he can only be seen from the neck down; but his face has made two separate appearances. Once in the "Sista Spice" episode, and in The Proud Family Movie when they were swept by the peanut butter. Wizard Kelly has Arnold Schwarzenegger-like employees. He is a retired former professional basketball player who made millions creating several entertainment properties.
He also has a twin brother named Lizard who runs the UBC television network. He owns many stores and businesses in town which makes him the mayor. He has a son named after him and a wife named Ginger S. Kelly. He also has a pet alien named Spats.
- Ironically, it was revealed in "One in a Million" that if Oscar had never missed that shot during the big basketball game, Oscar and Wizard would then have each other's lives.