Mombi is a fictional character in L. Frank Baum's classic children's series of Oz Books. She is the most significant antagonist in the second Oz book The Marvelous Land of Oz (1904), and is alluded to in other works. Mombi plays a very important role in the fictional history of Oz. Furthermore, Mombi had enslaved Ozma's father (King Pastoria) and grandfather, thereby removing the Royal Family of Oz, and enabling herself and the Wicked Witches of the East, West and South to conquer and divide the land between them.