The kids need Denver out of the way while they prepare a surprise birthday party for their dino-pal. But dino-sitter Freddy Facknitts gets them both into trouble when his "space ship" puts Dr. Funt, who thinks he is an alien from outer space, on their tail.

Mario and Shades get jobs working for competing fast food stores, which jeopardizes their friendship, and eventually sparks a rivalry between them.

Denver is put through his paces, participating in an exercise program with the kids while trying to hide a mischievous baby gorilla.