Furfur

Image of Furfur from Collin de Plancy's Dictionnaire Infernal.

In demonology, Furfur (other spelling: Furtur, Ferthur) is a powerful Great Earl of Hell, being the ruler of twenty-six legions of demons. He is a liar even when compelled to enter a magic triangle, where he answers questions, speaking with a rough voice. Furfur causes love between a man and a woman, creates storms, tempests, thunder, lightning, and teaches on secret and divine things.

He is depicted as a deer or winged deer, and also as an angel. To some authors he changes from deer into angel when compelled to enter the magic triangle.