The Devil Bat is the official mascot of the Deimon Devil Bats, the American football team at Deimon Private Senior High School around which the series revolves. Its design is that of a red, bat-like creature with horns and a tail, closely resembling the common visual stereotype of a devil. The creature is a fictional representation of a rare breed of bat that is said to resemble the team's captain, Yoichi Hiruma. The mascot's appearance is used as the team's logo, and it appears as a living character primarily within the anime adaptation.

In terms of personality and role, the Devil Bat serves as a cheerful and informative guide. Its main function within the anime is to host a segment called the American Football Clinic, during which it explains the rules, strategies, and terminology of American football to the audience. Through this role, the mascot helps viewers who may be unfamiliar with the sport understand the action taking place in the matches. The Devil Bat does not have a personal storyline, character development, or direct relationships with the human players; it exists outside of the main narrative as a playful, educational presence. Its motivation is purely to assist the viewer by clarifying the game's mechanics. The mascot does not possess any athletic abilities or participate in the competition itself. Instead, its only notable ability is its role as a knowledgeable and approachable teacher of the sport. The Devil Bat's consistent presence throughout these informational interlude segments makes it a recognizable and beloved symbol of the team and the series, but it remains a static character with no arc or personal growth.