Marilyn Munster was the only human in The Munsters’ monster-filled family, though her actress was recast after only 13 episodes. The Munsters’ progressive 1960s satirical sitcom followed a benign family of classic monsters living in suburban America, made up of Herman Munster (Frankenstein’s monster), his vampire wife Lily, their werewolf son Eddie, Lily’s father Grandpa (Count Dracula), and Lily’s completely normal human niece Marilyn. Out of the 70 episodes in The Munsters’ original run, Marilyn was the only main character to be recast aside from Butch Patrick replacing Eddie after the unaired pilot.

Contributing to The Munsters’ satire of gothic monsters posed as a quintessentially American family is Marilyn Munster, styled after actress Marilyn Monroe, who is frequently ostracized by her family for her “plain” looks. While it’s never revealed why Marilyn lives with her aunt and uncle in The Munsters' Mockingbird Lane house rather than her Transylvanian parents, or why she goes by the Munster surname, Marilyn resides with the family throughout the series while attending a nearby college. Marilyn Munster’s character was originally played by actress Beverley Owen throughout the first 13 episodes until she was recast with Pat Priest. Since Marilyn was the least present of the main characters and both actresses were styled similarly to Marilyn Monroe, her recasting wasn’t too noticeable.

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After starring in The Munsters for less than half of one season, Beverley Owen decided to depart the series for personal matters. According to USA Today, Owen left The Munsters in order to get married to Sesame Street writer Jon Stone and move to the East Coast when she was 27 years old. Needing a new Marilyn who would still reflect their Marilyn Monroe inspiration, The Munsters' original character was recast with Pat Priest, who had previously acted on the stage and in minor roles in two films. Even though The Munsters’ opening credits were reshot with the new Marilyn Munster actress, many viewers didn’t notice the recasting due to Beverley Owen and Pat Priest’s close physical resemblance.

Beverley Owen and Pat Priest as Cousin Marilyn on the Munsters

Although it was 13 episodes before Marilyn Munster changed actresses, it appears Beverley Owen’s time on The Munsters would have ended sooner if she had her way. After originating Marilyn in the pilot, Owen was required to continue portraying the role under contract with Universal Studios, which meant she had to move from New York to California. Away from Stone, whom she would soon marry, Owen was reportedly depressed and often seen crying onset of Universal's The Munsters, with the actress hoping desperately to be released from the classic show. Butch Patrick told Seattle Times that Owen’s pain from being away from her boyfriend was so severe that the Grandpa and Herman Munster actors marched into Universal saying that if they didn’t let Owen out of her contract, the entire cast would walk and they wouldn’t have a show.

The book Street Gang: The Complete History of Sesame Street alleges that Owen acting out on The Munsters’ set was staged, as she and Stone arranged them in an attempt to make the show release her so she could move back to New York full-time. The plan worked, and Universal Studios allowed Owen to leave The Munsters’ black-and-white show while Pat Priest took over. Once Priest was recast for The Munsters, she remained in the role for the rest of the original series, which ended prematurely in 1966. However, the recasting of Marilyn Munster wouldn’t stop there, as Priest was overlooked for the 1966 color Munster, Go Home! movie, which cast Debbie Watson in the role instead.

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