Wonder-Dog is the superhero alter-ego of Ace Hart, who makes his first (and last) appearance in the Dog City episode "Ya Gotta Have Hart." Ace is starring in his own comic book, but to the surprise of both Ace and Eliot Shag, the editor made some last minute alterations, turning the script into a superhero origin story. In a parody of the famous Superman radio show opening, the announcer further states that Wonder-Dog is faster than a speeding bulldog, more powerful than a pack of pumped up pups, and able to leap tall fences in a single bound.