Sharptooth is dying of boredom, so he tells Dr. Liz Caper and his brothers that he's going for a stroll in the park for some fresh air. Then before he knows it, a little 12-year-old girl named Hillary McLeonard catches his eye, and he befriends her. Meanwhile, Vicious Victor, that nasty slime ball, is planning to destroy San Diego with a lava cannon that can shoot lava from the earth's core. Sharptooth must get help and stop Vicious Victor before he makes anymore destruction, then he'll introduce Hillary to his brothers after that. When Hillary gets home and tells her parents she met Sharptooth, they think he's her imaginary dinosaur friend and don't believe her.
