The Cruel Vet is responsible for separating Courage from his parents as a puppy. He captured them, put them in a rocket ship, and sent them to the moon, believing they would turn into superdogs. However Courage escaped from this fate and was adopted by Muriel. The vet later tries to do the same thing to Eustace, Muriel, and Courage years later but is sent to the moon himself, where he finds that all the dogs survived, including Courage's parents. Out of pure anger, the dogs proceed to viciously (off-screen) maul him. This episode can be considered a true series finale due to finishing Courage's story.