Umb is the king of the Magical Mimics of Mount Illuso.
Description[]
Since Umb regularly changes his shape among a range of foul choices (like all Mimics), a physical description has little point. (He might choose a bear's body with an owl's head, or a gray ape with cloven hooves and a human head.) In personality he is tough and brutal, and as evil as any of his subjects. He has little skill in magic, though, and in that craft and in sheer cunning malice he is overshadowed by his wife, Queen Ra. (The Magical Mimics in Oz)
Background[]
Umbra is the Latin word for shadow.
In their marriage, Umb is the brawn and Ra is the brains. Their relationship resembles that of King Gos and Queen Cor in Rinkitink in Oz.