As a boy, he won Rover at a carnival. He kept him as a pet, until his father flushed Rover down the toilet. Cap never forgot about Rover, even pursuing a career as an alligator hunter in hopes of one day finding his old pet. That day came when Rover was discovered at Shelter 17. Cap was called in, and captured Rover. Soon after, the two discovered who they were, happily reuniting.
Cap Wilder's real name is Jimmy.