In the 1st episode, The Munsters are invited to a masquerade party by Marilyn’s boyfriend. Everyone is shocked when Herman wins…little do they know, it's one mask under another, or so they think. .
The Munsters

The Munsters was one of the two "creepy" sitcoms that began in 1964. CBS aired The Munsters and ABC aired The Addams Family. Both of them lasted only two years and finished their network run within a week of each other.
After another date runs away, Grandpa develops a love potion intending to help Marilyn. Unfortunately, things don't go as planned.
Herman struggles with insomnia. As a remedy, he decides to go walking through the park, where there are reports of a monstrous villain.
By accident, Herman and Grandpa overhear a conversation that gives them the impression that Lily is pregnant, but, little do they know, they'll soon find out they couldn't be further from the truth.
When the gas company decides to run a new pipeline, it poses a problem for the Munsters. At the depth the gas company is planning it would send the pipe right through Grandpa’s lab. Work presses on till the workers are frightened by the way the Munsters look.
An army reunion looms and Herman wants to attend. He wants to wear his uniform, but has gained too much weight. He visits Dr. Dudley to see if a diet would be healthy. After strange occurrences, Dr. Dudley tells Herman he will be dead if he doesn't go on a diet.
With expulsion from school a possibility, Grandpa helps Eddie create a robot. Herman is mistaken for the robot, winning Eddie first place.
Herman bends a metal pipe in front of one of Eddie's friends, whose father is a wrestling manager. The father recruits Herman--who becomes a disguised wrestler under the appellation of "The Masked Marvel." Herman, however, is a natural loser as he listens to the sob stories of his opponents and lets them win.
When Herman’s brother Charlie shows up, it can’t be a good thing. Charlie is a con-artist and coincidentally Lily just inherited five thousand dollars.
All alone and depressed Grandpa heads for a match making agency to help him find love. An elderly woman shows up and they hit it off. She turns out to be a black widow…ready to take Grandpa for all he is worth.