Good Boy! is a comedy film that tells the story of a young boy and his strange new dog. Owen Baker (Liam Aiken) has been asking his parents for a new dog all his life. Each time, his parents refused, claiming he wasn't responsible enough. Owen agrees to prove his maturity by working as a dog walker for his neighbors. He works hard and his parents finally buy him a dog of his own that he names Hubble (Matthew Broderick). There is more to Hubble than anyone can see, however. He is an alien visitor, sent to earth to figure out why the dogs (a species of extraterrestrials sent from the Sirius star system) have yet to invade earth and report back. He is shocked to find that the dogs of earth have gotten lazy and no longer want to invade. It is up to him to rally the canines of earth and move forward with the invasion.