Segal opens the story on a dark dream indulged by the professor, beginning with vows he is taking in a marriage ceremony with the lovely Denice and ending with the scattering of the entire church party when the loud and arrogant Buddy Love springs from his pants. Recall from "Nutty 1" that the massively overweight Sherman had swallowed a serum for re-aligning his genetic structure, which transforms him into a well-toned alter ego, Buddy Love. While the new man is a sight for the sore eyes of any young and beautiful maiden, his personality is conversely obnoxious. This time around, using biology professor Denice Gains's strategy for changing his genetic structure, Sherman is finally able to remove Buddy from within his body, but having done so, Buddy turns on his creator and embarks on a plan to steal Sherman's formula for restoring youth to aging bodies and gain the $150 million offered by a large pharmaceutical company for its rights.

To pull in the large numbers of movie fans who have shown themselves insatiably addicted to toilet jokes, the four writers have implanted a series of occasionally funny but mostly mind-numbing and sit-comish incidents into a sadly fragmented and incoherent script. In one episode perhaps intended to spoof the 1950s sci-fi genre, a giant hamster is created when the professor's youth serum liberates dangerous side effects, a rodent which attacks its enemies by hurling its wastes scattershot into its audience, felling even a policeman with drawn gun as though attacking with the Redcoats' cannonball firepower in "The Patriot." Since the hamster makes love as well as war, it seizes the opportunity to jump the college dean (Larry Miller) while the administrator is attempting to escape, haplessly, while wrapped in a blanket of fur.

But the hamster is not the most irritable character in this splintered, would-be comedy. The prize for that attribute can be shared more or less equally with the Klump family, all of whom are played by Eddie Murphy utilizing the ingenious disguises of Rick Baker's makeup. While much credit need be given to the special effects department for allowing the interaction to take place as though the Klump family were indeed a half dozen separate people, each member of the group competes for the title of most vulgar, and the jury may still be out on whether the hamster has routed the Klumps in that department. Mama and Papa Klump advance a running gag on sexuality, with Mama trying ever-so-hard to turn on her defensive and seemingly reluctant husband in scenes that could remind TV viewers of a similar running gag on "Married...with Children." The octagenarian Grandma Klump in one gross-out scene attempts to seduce young Buddy Love, having surprised the much younger man in the garage of the Klump household: "This must be your lucky night."

While the majority of the audience will probably reject this counsel, director Segal would have done better to emphasize the romance between the obese but charmingly shy Sherman and the lovely woman of his dreams. Both are as intelligent as they are decent and down-to-earth and both deserve far greater time than Segal and his trigger-happy editor, William Kerr, afford them.