Mooch has a good heart, but Buster doesn't see much use for him other than to crash through fences so he can get through (as Buster was incapable of unlocking gates by himself). Mooch has only but heard tales of Tramp, and they're pretty exaggerated. He eventually leaves the junkyard with the other Junkyard Dogs minus Buster, and gets adopted by a family.
He bears a similarity to Prince Eric's dog, Max, as they are both the same breed.
His voice is similar to Patrick Star from the Nickelodeon tv series, SpongeBob SquarePants.