Some years after the previous film, Dennis Mitchell (Justin Cooper) is worse than ever. At the beginning of the film, he goes over to the house of George Wilson (Don Rickles) to offer him some pets as gifts for his birthday. They include frogs, lizards, snakes, insects, tarantulas, scorpions, mice, exotic mammals, and even a baby alligator. This ordeal ends with George unintentionally riding down a flight of stairs in Dennis' red wagon and accidentally getting his birthday cake thrown in his face by Martha (Betty White).