Grandpa mixes up a love potion designed to make the opposite sex fall madly for anyone who drinks it.

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.

The gas company wants to run a pipeline 25 feet under the Munsters’ house. However, at that depth it would run through Grandpa’s dungeon lab...

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...

Thanks to a recommendation from an investigator of The Board of Education, Eddie is in danger of being expelled from school. The only way he can stay is if he makes an excellent project for the school’s Science Fair, so Grandpa helps him make a robot.

Herman becomes a professional wrestler called The Masked Marvel. After he shows that he has superhuman strength to a friend of Eddie’s who is the son of a pro wrestling manager. Herman uses the extra cash to save for Eddie’s college education. However Herman is so nice and gullible his opponents can take advantage of him.

Herman has a twin brother Charlie who is a con-artist. He comes to town and ends up stays at the Munster home, which doesn’t make Herman too happy. Charlie claims to have made an invention that takes uranium from seawater, he’s looking for an investor. Herman thinks that the whole thing is a scheme to get a Lily’s $5000 inheritance, he ends up being right.

Grandpa is feeling lonely and depressed so he contacts a matrimonial agency to find a mate. The agency sends over a nice looking elderly woman who find Grandpa to be delightful. She turns out to be the Black Widow: she makes her living by marrying her suitors, getting them to sign a life insurance policy naming her as beneficiary, and then murdering them.