Kuro Kirigakure is a demon cat known as a 'Cait Sith' in the anime and manga series Ao no Exorcist (Blue Exorcist). Originally the familiar of Shiro Fujimoto, he becomes Rin Okumura's companion after Shiro's death. Despite his intimidating size and demonic powers, Kuro is playful, loyal, and sensitive, often helping Rin and his friends. His transformation abilities and deep emotional bond with his masters make him a unique and memorable supporting character in the series.