This one was a toss-up between the demonic dog Black Shuck and the demon Buer. I decided to go with Buer simply because I'll probably write about Black Shuck in a later post. (He's a character in a couple of my stories.)
Anyway, Buer is served by 50 legions of demons and is also the character in Dzieje Mistrze Twardowskiego (a Polish film based on Faust), according to Finlay Cowan's Dragons and Fantasy Beasts. (I love foreign films and this isn't available on Netflix. Grr...)
Sorry. Distracted. Buer has a lion's head and five goat legs (Cowan). According to The Dictionary of Demons (Michelle Belanger), Buer "teaches a wide variety of disciplines, from moral and natural philosophy to logic. He also teaches the virtues of herbs and can heal disease... He is constrained by the angel Aladiah."