While the movie draws on many elements of the original series, it departs from the established "Munsters" canon. In this version Marilyn's last name is given as Hyde and she is the daughter of Herman's sister, not Lily's (as she is in the original series and in "The Munsters Today"). Also, in this film Marilyn is the same age as she is in the series, however Marilyn has said in the original series that Herman and Lily have raised her since she was a baby.
This film deviates from the classic "Munsters" storyline, modifying key aspects of the characters' histories and family dynamics. Specifically, it alters Marilyn's surname to Hyde and her parentage, diverging from the original series and its spin-off "The Munsters Today".