Karasu Tengu, whose name translates to Crow Tengu, is a yokai who serves as one of the primary advisors to Nurarihyon, the Supreme Commander of the Nura Clan. He is characterized by his distinct appearance, being a small, crow-headed yokai with a large, round head, a small beak, tiny red pupils, and a dark red, gem-like mark on his forehead. His attire traditionally consists of a cream-colored robe, prayer beads around his neck, and tabi on his feet, and he possesses large wings that enable flight. In the narrative of Nura: Rise of the Yokai Clan, particularly during the Demon Capital arc, Karasu Tengu is a loyal and long-standing member of the clan who has been with Nurarihyon for centuries. Four hundred years prior to the main events, during Nurarihyon's prime, he was depicted as a much larger, anthropomorphic crow who actively fought on the front lines of the clan's battles. One notable conflict from this era was a clash between the Nura Clan and the Gyuki Clan, where Karasu Tengu fought against Gyuki before the latter group was eventually subjugated and incorporated into the Nura Clan. He also participated in the great battle against Hagoromo Gitsune's forces at Osaka Castle, where he faced the yokai Kyokotsu; their duel ended inconclusively when Hagoromo Gitsune was defeated by Nurarihyon.

In terms of personality, Karasu Tengu is defined by his profound loyalty and devotion to the Nura Clan, particularly to its leader, Nurarihyon. This allegiance is so strong that it translates into visible anxiety and distress when Nurarihyon is absent. For instance, when Nurarihyon disappeared to travel to Shikoku, Karasu Tengu spent a great deal of time flying over Ukiyoe Town in tears, frantically searching for him. His role in the story is primarily that of a supporter and advisor, often seen giving orders and managing situations rather than directly engaging in combat in his later years. Despite his advanced age and reduced stature, his past as a formidable warrior indicates that his abilities are not to be underestimated. His notable abilities include flight with his large wings, and he possesses centuries of combat experience, having fought against powerful yokai like Gyuki and Kyokotsu. In the Demon Capital season, he appears in a practical capacity, such as when he returns the young protagonist Rikuo Nura to his home after the boy misses the last school bus. Karasu Tengu is also a parent; he has three children known as the Sanbagarasu, consisting of two sons and one daughter. Throughout the series, while his physical role as a front-line fighter diminishes, his development is reflected in his unwavering constancy as a trusted retainer and his continued service to the Nura Clan's leadership, first under Nurarihyon and then in support of the young heir, Rikuo.