Enigmatic, is a good way to describe Carl Stevens. Stevens provided the voice of young Fred Jones in the Pup Named Scooby Doo series and sent us on wild goose chases by always blaming everything on the "Mud Monsters" and "Red Herring."
There is very little information out there about Stevens. Other than his voice over work on the Scooby series, Stevens does not appear to have done much additional voice over work. The most notable was his voice work as Franklin in a Charlie Brown show.
Stevens does have a healthy list of television shows and movies where Stevens has appeared on camera. For example, he was the young spock in Star Trek: The Search for Spock. He has also appeared on E/R, Punky Brewster, Growing Pains, and a lot of other popular shows dating all the way back to a 1981 episode of Little House on the Prairie.