The names of God's fallen angels include Lucifer, who in Christian lore became Satan after his fall, and the angel Belial, also associated with Satan. Beleth is also one of the most powerful fallen angels.
Beleth is a demon king who rules over 85 legions of demons and appears with a blast of trumpets on a pale horse when he summoned.
Abbadona was once the great friend of the angel Abdiel. He was once a seraphim and believed to be remorseful for his apostasy. Christian theologians reject this however. Since Abbadona is now a demon, he can only think evil thoughts, and he cannot repent.
Samyaza was the leader of a group of angels called the Watchers, according to the Book of Enoch. They fell not because of disobedience to God, but because they lusted after human women. They sired children with these women, and the children became the Nephilim, a race of cannibalistic giants. Samyaza and his cohort also taught humans the art of war and other dubious practices.
Caim rules over 30 legions of demons. He takes the form of a thrush or a blackbird. He can also take the form of a man wearing a headdress and a peacock's tail or a man carrying a sword.