Princess Mombi is a head-switching, beautiful and tyrannical sorceress who commands the maniacal Wheelers, and she is also one of the two main villains alongside the Nome King who attacked and took over the Emerald City of Oz in the 1985 Disney movie Return to Oz.She was portrayed by Jean Marsh, (as well as Sophie Ward and Fiona Victory), the same actress who plays Head Nurse Wilson in the mental hospital where Dorothy is committed at the beginning of the movie.
Princess Mombi is a dark-haired, deranged and evil middle-aged sorceress. She is a coward at heart who grovels before the Nome King and begs for her life when he is displeased with her. She makes a deal with the Nome King, for if she trapped Princess Ozma in her enchanted mirror, he would make her a queen and gives her thirty beautiful heads which she could switch depending on her mood. He also gives her the Emerald City as her own kingdom, after he took away the emeralds. She also guards the Powder of Life. When Dorothy encounters "Princess Mombi" in her palace, Mombi develops a fondness for Dorothy's head and locks her in the tower, planning to remove her head and take it once the girl has reached adulthood. Dorothy however escapes and steals the Powder of Life from a case which also contains Mombi's true head. Unfortunately, she awakens the head which screams Dorothy's name, awakening the other heads in turn which all begin screaming her name as well, ultimately awakening Mombi's headless body which relentlessly pursues Dorothy who manages to escape. Donning her true head, Mombi sends her sinister minions, the Wheelers after Dorothy. At the climax of the film, the Nome King imprisons Mombi in a magical cage for failing him. Mombi is stripped of all her magical powers at the end of the story.
This characterization of Mombi was combined with head-exchanging Princess Langwidere from the third book in the series, Ozma of Oz.