Young boy violinist from the "Capt. Marvel Jr. and the Great Dischord" story of comic book Captain Marvel Jr. #59 (March 1948). While in town for a concert at the Avon Theatre, John gets weary of performing and is desperate to accomplish some... thing. So he sneaks out of the theater, and with zero experience tries his hand at operating a crane and fixing an airplane, with expectedly disastrous results. Capt. Marvel Junior saves him each time, and when he realizes it's Fidler, talks him into getting that feeling of accomplishment by satisfying his audience at the Avon Theatre that night.