Ukobach (ウコバク Ukobaku) is Mephisto's familiar and a stove spirit who prepares Rin and Yukio's meals. He developed a close bond with Rin through their mutual love for cooking. He only appears in the anime.
Ukobach is a satyr-like Demon. He can transform into a larger minotaur and appears from thunder strikes for comedic effect. He has yellow eyes.
Ukobach is proud of his cooking skills, but also fiercely protective of his food and his domain, the dorm kitchen. As such he was enraged at Rin for using the dorm kitchen without his permission and for a while he refused to cook for the brothers. He also tried to cook 3 girls for ruining his lunch for Rin and Yukio. He is often silent, but Rin has been able to communicate with the little Demon and the two get along well due to their mutual love of cooking.
True Cross Academy arc
Rin and Yukio find that the one responsible for their meals at the dormitory was Ukobach, a cooking familiar appointed by Mephisto Pheles to aid them. Later, Rin befriends Ukobach for their interest in cooking. But the brothers learn how Ukobach can be troublesome when he gets angry.
Powers & Abilities
Expert Chef: Ukobach has incredible cooking skills, and is able to prepare delicious meals for both humans and Demons.
Enlarged Body: Ukobach has the ability to enlarge his body, giving him greater strength, similar to Kuro's ability to change from a small cat to a nekomata.
Appearances in Other Media
Ao no Exorcist Movie
Ukobach makes several cameos during the movie, all of which take place in the kitchen, where he has back turned to the camera.