Taking place in a flashback during Joker, Spade, and Queen's childhood, a mutant dog known as Super Dog #101 was created in a laboratory and escapes along with a mutant lizard who wants to destroy the human race. He gets injured, falls into a river, and later gets saved by Joker, Spade, and Queen while they were fishing. They name the dog "Roko" after its love for corn and are told by it about the lizard's plan. They decide to pursue the lizard in order to save the human race.