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.

Eddie is upset that his family does not treat him cruelly because he thinks this means they don’t care about him. When Eddie decides to run away from home, Herman employs a little child psychology, which naturally backfires. Various circumstances eventually lead to Herman’s getting involved with a dancing bear.

Grandpa’s magic transforms Eddie from a rotten trumpet player into a classical music virtuoso. But when he needs to duplicate the potion for a command performance for Herman’s boss, Grandpa can’t remember the exact formula. Eddie is accidentally turned into a jazz-playing, jive-talking hipster.

Eddie longs for the companionship of a younger brother, so Grandpa builds him a robot named Boris. Eddie becomes resentful of this silent, mechanical boy who is so considerate and well-behaved that he garners all of Herman’s attention and admiration.

Grandpa feels neglected and decides to depart the Munster Family. In the beginning Lily and Herman believe this is just a ploy to get attention and they let Grandpa leave, expecting he’ll soon come back. Shortly afterwards, they begin to miss him and try to track him down. The find out he’s doing a magic act at a local nightclub.

In order to accompany Marilyn to her school dance, Herman decides to take dancing lessons. He goes to Happy Havemeyer’s Dancing School, where he is suckered into signing a ten-year contract for 1500 lessons (at $7.50 a lesson). Herman is under the wrong impression that he is going to become a dancing instructor for the school.

After Herman attends an office party that goes on until the wee hours of the morning, Lily locks Herman out of their bedroom and makes him sleep on the sofa. When they are unable to reconcile, Lily and Herman each see a marriage counselor independently.

Grandpa is under the impression that he’s turned Eddie’s friend Googie into a monkey. The truth is that the little boy is hiding to fool the Munsters.

In yet another example of Eddie’s misguided regard for his father’s natural abilities, the young Munster enters Herman’s name in the bucking bronco contest at the local rodeo. Lily is unable to talk Herman out of such a dangerous task: he is intent on being a hero to his son in spite of the fact that he’s scared stiff. Meanwhile, the promoters plan to have Herman ride a horse that is guaranteed to break every bone in his body.

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.

In order to accept a promotion, Herman has to shuffle his family off to Buffalo. Eddie, who happens to be doing great on the baseball team, throws a temper tantrum. Since Grandpa has already sold the house to a wrecking company, the Munsters have no choice but to wage war.

A 300-pound safe drops on Herman’s head, causing him to develop amnesia. In order to get him released into her custody, Lily petitions the court to adopt Herman as her son. Until he restores his memory, he is treated as Eddie’s brother John.

The Munsters’ pet Spot runs away from home and is mistaken for a dangerous monster when he is sighted in the sewer. When Herman goes down the manhole to search for Spot, he too is mistaken for a dangerous monster. The Mayor vows to rid the city of these menaces by using TNT.

Herman advises Eddie to turn the other cheek when he gets pushed around by a bully. Shortly thereafter, Herman is the victim of a practical joke at work. Grandpa takes the situation in hand by teaching both Eddie and Herman how to box.

A lady in Sioux City, Iowa, has placed an advertisement offering a reward for the return of her lost husband, who is Grandpa. Grandpa claims to have never seen this woman before in his life – but when he discovers that she’s filthy rich, he’s ready to sign an affidavit stating that she is his spouse.

After Herman has his poetry published in The Mortician Monthly, a shy coworker named Clyde asks him to compose love letters to help him attract the attention of a young lady he’s fallen for. Herman obliges, but soon Lily discovers samples of this mushy writing and becomes suspicious. After a re-enactment of the “hiding in the bushes” scene from CYRANO DE BERGERAC, the object of Clyde’s desire falls for Herman. Meanwhile, Herman mistakenly suspects that Clyde’s object of desire is Lily.

Dr. Victor Frankenstein IV from Germany visits Mockingbird Heights and brings with him Johann, Herman’s look-alike cousin. Johann is quite primitive and behaves like the Frankenstein monster from the movies. It is up to Herman to try to civilize him and teach him English. Lily is not informed of this; mistaking Johann for Herman, she takes him away for a romantic weekend getaway.

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.

After going to the car to find something Herman falls asleep in the back of his car with the keys in the ignition. The car is then stolen by bank robbers who don’t know that Herman is sleeping in the back seat. When Herman wakes up he wanders into their hideout and is thought to be Big Louie, a gang member who has taken twenty years of beatings in the boxing ring. Herman winds up as an accomplice in a bank robbery.

Eddie wants to quit school because all the kids there call him Shorty. Grandpa helps by fixing a potion to make Eddie grow six inches overnight. Instead, the potion causes the young Munster to grow a full beard and mustache.

When Herman and Grandpa go to the bank to make a withdrawal, they are mistaken for bank robbers and handed eighteen thousand dollars in cash. When Herman gets home and realizes the wrong he’s done wrong, he can’t rest until he returns the money. When trying to bring it back in the middle of the night, Herman and Grandpa wind up locked in the bank’s vault.

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.

Herman becomes insanely jealous of Chester, a mysterious boarder whom Lily has bought into the household in yet another of her schemes to acquire a little extra cash. After searching Chester’s room, Herman concludes that he’s a gangster. In fact, he is a lieutenant for the police department.

The Munsters are heading for a vacation in Buffalo Valley when Herman gets off for a rest stop at Indian Flats. He wanders into the village of an Indian tribe that specializes in luring the tourist trade. The tribe’s eldest member mistakes Herman for an ancient spirit leader.

Marilyn’s boyfriend, Tom Daily, invites the Munster clan to a masquerade. Eddie remains at home with Mrs. Morton as his sitter. Marilyn goes as Priscilla, Lily is Little Bo Peep, Grandpa is Napoleon and Herman is King Arthur in a suit of shining armor.