Herman is suffering from insomnia. The only thing that will make him sleep is a late-night walk in the park. A 'monster' type creature has been spotted in the park at night and Lily would prefer if Herman would stay home. What she doesn’t know is that the monster is Herman!

Herman and Grandpa overhear Lily and Marilyn talking and somehow get the idea that Lily is pregnant. What’s really happening is Dr. Dudley’s son, Elmer, is coming to stay with the Munsters while Dr. Dudley and his wife are on vacation.

Herman wants to go to a reunion with his army friends. Unfortunately he can’t seem fit into his uniform. Lily doesn’t want him to go, but decides to make a deal with him. If he can lose enough weight to fit into the uniform, he can go...

Marilyn has insomnia and in a attempt to cure it, Grandpa accidentally gives her a Sleeping Beauty potion instead. Now Marilyn can’t wake up unless she has been kissed by a prince. Lily and Herman advertise for a prince in classified section the newspaper, but this only attracts a couple of out-of-work actors. Meanwhile, Grandpa is negotiating with an oil company for the rights to use his magic pill that turns water into gasoline.

When Herman fools around with a ham radio in Grandpa’s dungeon, he thinks he’s contacted Martians. But he is actually speaking to two kids who are fooling around with walkie-talkies and just pretending to be Martians. The kids think Herman is also a kid, and a stupid one too.

Eddie volunteers Herman as a performer for his school’s Talent Night. Since Herman has no discernible talent, Grandpa conjures up a pair of magic ballet shoes that will transform whoever wears them into a gifted dancer. But Herman is uneasy about strapping on this footwear. Fortunately, Eddie already has him billed as the world’s greatest magician.

Eddie, under the impression that his father is the greatest driver in the world, volunteers Herman in a drag-strip competition. After souping up the Munster Coach and dressing up like Marlon Brando in his Wild One days, Herman loses his car in a drag race. In a rematch, Grandpa races in the Dragula, a motorized coffin on wheels.

Herman saves the life of a young boy, Galen Livingston Stewart, by bending the bars his head is stuck between. They immediately become close friends. The only problem is that Galen’s parents think Uncle Herman is a figment of the boy’s imagination. They take him to a psychiatrist, played by Harvey Korman with a broad German accent.

When Eddie is called Lead Foot by the other kids on his track team, Herman offers to become his athletic coach. While demonstrating his out-of-this-world prowess in shot put, discus-throwing and pole-vaulting, Herman causes untold destruction and makes a fool of himself. Grandpa decides to come to the rescue by creating a magic speed pill that will make Eddie a champion runner.

When Herman visits the hospital to see Eddie, who is having his tonsils out, he is mistaken for an accident victim and is immediately given a dose of laughing gas. Grandpa rescues him and brings him home, where Lily assumes that Herman has been drinking.