Peter Puppy is the sidekick of Earthworm Jim in the show of the same name. He is neurotic and nervous, but when it comes to Jim, he is brave. Whenever he gets angry, scared or hurt, he would turn into a giant monster ready to attack. He is normally a light yellow dog with black ears, a teal unbuttoned t-shirt/jacket and black shorts. He is voiced by Jeff Bennett.
Before prior to the show, he was just a normal dog until Evil the Cat gave a spell that not only gave him speech, brains and the ability to walk like a human, but whenever hurt or angry, would turn into a monster. No one knows how he met Jim, but whenever they're in a jam, they stick together. Sometimes, Peter would say a moral at the end of the adventure to which Jim would take.