Ukobach

ウコバク

Ukobach serves as Mephisto's familiar and acts as a stove spirit who prepares meals for Rin and Yukio. He formed a close bond with Rin through their shared passion for cooking.
Ukobach resembles a minotaur-like demon. He has been observed transforming into a larger minotaur and emerging from thunder strikes, seemingly for comedic effect.
Ukobach takes pride in his culinary skills, yet he is fiercely protective of his food and his domain, the dorm kitchen. Consequently, he became enraged at Rin for using the dorm kitchen without permission and refused to cook for the brothers for a period. He also attempted to cook three girls for ruining his lunch intended for Rin and Yukio. Although he is often silent, Rin has managed to communicate with the small demon, and the two get along well due to their mutual love of cooking.