The Yoop is a fierce cannibal giant who is imprisoned in a mountain cave in the Quadling Country. He is the largest untamed giant in captivity.
Description[]
The Yoop is 21 feet tall, and weighs 1640 pounds; he is at least 400 years old and has a deep bass voice. His temper is fierce and ferocious, with a ravenous appetite, preferring Meat People and Orange Marmalade. Since his imprisonment he has had only six ants and a monkey.
He is dressed fancily, in a pink velvet suit with silver braid and buttons, pink leather boots with tassels, and a hat with an enormous pink ostrich feather. (The Patchwork Girl of Oz)
When he was roaming free he ate cows and sheep and sometimes knocked over people's houses. He is (or was) married to Mrs. Yoop, a powerful Yookoohoo; she also was a giant, but he does not share her magical abilities, and cannot transform himself to escape from his confinement. Since he abused his wife in the past, she was never willing to use her power to free him. (The Tin Woodman of Oz)
Background[]
Since Mrs. Yoop was transformed into a green monkey by Princess Ozma, some aspects of the status of the Yoop and his Mrs. are unclear; such as whether or not turning into a green monkey can affect one's marriage vows, etc.
Paul Dana provides an origin story for the Yoop in his novel Time Travelers of Oz.