Mad scientist Dr. Henry Augustus Wolfgang, aided by his hunchbacked assistant Floop, embarks on a bizarre quest to assemble a monstrous creation using body parts. They begin by robbing graves, and during their escapade, Wolfgang unwittingly kills the zombie pianist Franz Pennywhacker by striking him in the head. However, Floop mistakenly grabs the head of the not-so-funny comedian Shecky Von Rathbone instead of Shecky's astrophysicist brother Shelly, who was Wolfgang's actual target. Through a jolt of electricity, Wolfgang brings to life his twisted creation, who is affectionately dubbed "Herman Munster" by Floop.
In a subplot filled with intrigue and deception, the vengeful Zoya Krupp, portrayed by Catherine Schell, uses her charms to manipulate the Count's werewolf son, Lester, into her scheme. Claiming that Lester owes her money, she threatens him with the fate of being beheaded by her formidable brother Bela unless he convinces the Count to sell her his Transylvanian castle. Zoya's ultimate goal is to transform the castle into a bustling casino and theme park, but the Count, Daniel Roebuck, quickly dismisses the idea.
As breakfast is served by the devoted servant Igor, the Count and his ancient vampire daughter Lily Gruesella discuss her disappointing romantic escapades, which notably include a lackluster date with Count Orlock. Their conversation is interrupted by the morning TV show Good Morning Transylvania, hosted by Ezra Mosher, who features Wolfgang for a live demonstration where he unveils Herman Munster to the world. Initially, Wolfgang is disheartened to see that his creation is a hapless oaf with a knack for comedic antics, yet Lily is drawn to Herman's quirky charm.
With Floop taking on the role of Herman's manager, Herman suddenly finds himself in the spotlight, which leads to a performance opportunity at Zoya's nightclub. Lily, directed there by Lester due to a hidden threat from Zoya, meets Herman and the two immediately feel a connection. They soon agree to a dinner at the Count's castle, prompting the Count to develop animosity towards Herman, seeing his simple-mindedness as a threat to his daughter. To resolve the conflict, the Count conspires with Igor and attempts to conjure a mate for Lily but ends up unintentionally summoning a semi-sentient chimpanzee instead.
As their romance blooms, Herman and Lily take a vacation to Devil's Island Penal Colony, where Lily joyfully accepts Herman's marriage proposal. The wedding signifies a shift in dynamics, establishing Herman as the new head of the household. However, Lester manipulates Herman into signing over the castle's deed to Zoya, lured by the promise of a grand business venture. The couple's happiness is further complicated when they honeymoon in Paris, where they encounter a reptilian creature and decide to adopt it, naming their new pet Spot.
As they return to Transylvania, tension rises when the Count confronts Herman over his dealings with Zoya. Meanwhile, Lily receives alarming news from the incarcerated Shady MaGoon about their shaky legal standing against Zoya, prompting Herman's decision to relocate to Hollywood to pursue stardom. Their real estate agent, Barbara Carr, shows them several properties, yet the Munsters are drawn to a rundown house at the infamous 1313 Mockingbird Heights address.
When Halloween arrives, the family finds themselves at a block party, mistakenly believing that all their neighbors are similarly eccentric. The townsfolk, convinced the Munsters are simply in costume, award them a $1,500 prize for their unconventional presence. As Herman navigates his new life, he shockingly realizes they now live among ordinary suburbs, sending waves of horror through the family. Just when things seem dire, Lester shows up with unexpected news: he presents Herman with a check from gambling winnings, revealing that Zoya's involvement may have inadvertently made them rich. Through comedic misadventures and supernatural complications, the Munsters’ journey unfolds, promising chaos and laughter ahead.
