Furfur, aka Furtur, is a powerful Great Earl of Hell ruling over twenty-nine legions of demons. He is a liar unless compelled to enter a magic triangle where he gives accurate answers to every question, speaking with a rough voice. Furfur causes love between a man and woman, creating storms, tempests, thunder, lighting, and blasts. Also known to teach on secret and divine things.
It also appears as a hart (an adult male deer, especially a red deer over five years old) with a fiery tail.
He is depicted as a hart or winged hart, and also as an angel. To some authors, he changes from hart to angel upon entering the magic triangle.