Azazel

Azazel is a villain on The CW Television Network's drama and horror television series Supernatural. He serves as the main antagonist during the first two seasons. As a demon Prince of Hell, he feeds his blood to infants so that they will grow up to develop demonic abilities. His goal of using one such child to release Lucifer is not revealed until much later in the series. Azazel is referred to by nicknames such as "The Yellow-Eyed Demon," or "Yellow Eyes" throughout the first two seasons, his true name not being revealed until the third season. Due to the character's demonic nature of taking different hosts, Azazel has been played by numerous actors but Fredric Lehne is the main default portrayer. All the incarnations have maintained his sadistic sense of humor and irony. Azazel's popularity and importance towards the franchise even led him to be the main antagonist and the analogue to Lucifer in the anime adaptation, as the "Yellow-Eyed Demon," in reference to the nickname he had in the original first two seasons.