Matthew Lesko is seen in a quickly flashed image at the end of the episode, The Dork Knight. He wears a suit covered with question marks, similar to the Riddler from Batman. Matthew Lesko in real life is also known to dressed in a question mark suit regularly. In the flash image, Matthew is attacked by Koala Boy (Doug in disguise as the superhero Batperson's sidekick).
Matthew Lesko is an American author, self-proclaimed federal grant researcher, and infomercial personality. He has authored over 20 reference books telling people how to get "free" money from the United States government.
He is popularly known as "that question mark guy" for the Riddler-like suits that he wears regularly.