Ukiki is a dark brown spider monkey. He sports a lighter shade of brown around his face, hands, feet, and ears. There are also pink “blushes” on his cheeks, and another on his nose. His eyes are beady and appear to be blue. He mouth consists of a curvy smile.
Ukiki only appears in Tall, Tall Mountain. He is the main antagonist of the second mission, "Mystery of the Monkey Cage", where he will steal the any of the character's (excluding Yoshi) Caps, which requires the player to chase Ukiki and take back their hat.
- Ukiki is not a specific character, but rather a member of a species with the same name that appears throughout the Mario series.
- Ukikis are also known (in other games) as "Grinders", or simply "monkeys".