Flannel is a major character in the story, Through the Looking Glass, which was originally owned by Shirou Fujimura before being adopted by Demons Anarchy of Pride, prior to it's publishing. He is a Lobo Demon, a race of monsters capable of transforming into wolf-like creatures. He, alongside the other servants, serve under Alice Liddell. As stated by Rias, if his group were considered a peerage, Flannel would be his Rook, alongside Metis.