DEMONS in the Ars Goetia
The demons' names are taken from the Ars Goetia, which differs in terms of number and ranking from the Pseudomonarchia Daemonum of Johann Weyer. As a result of multiple translations, there are multiple spellings for some of the names. 
 
According to le Grand Grimoire, Baal (or Bael) is the head of the infernal powers. Bael is first king of Hell with estates in the east. He has three heads: a toad, a man, and a cat. He also speaks in a raucous, but well formed voice, and commands 66 legions. Bael teaches the art of invisibility, and may be the equivalent of Baal or Baalzebub, one of the Seven princes of Hell.