Ben Healy and his social climbing wife Flo adopt fun-loving seven year old Junior. But they soon discover he's a little monster as he turns a camping trip, a birthday party and even a baseball game into comic nightmares.

Dr. Jack Hammond has best chances to become medical superintendent in the clinic. So he's completely absorbed in his work and has no understanding for his teenage son Chris' problems with school. By accident one of them drinks a brain-exchanging serum, and it switches their identities. This leads of course to extraordinary complications in school and at work, but also to insight in the problems and feelings of each other.

Chris is the top brain who just wants to party, Mitch is the 15-year-old college wiz kid. Supposedly hard at work on a lab project with a mysterious deadline, they still find time to use their genius to discover new ways to have fun.

A successful businessman falls in love with the girl of his dreams. There's one big complication though; he's fallen hook, line and sinker for a mermaid.

A nebbish of a morgue attendant gets shunted back to the night shift where he is shackled with an obnoxious neophyte partner who dreams of the "one great idea" for success. His life takes a bizarre turn when a prostitute neighbor complains about the loss of her pimp. His partner, upon hearing the situation, suggests that they fill that opening themselves using the morgue at night.