Astaroth (大魔王 アスタロト, "Great Demon Lord Astaroth") is the main villain of the Ghosts 'n Goblins games. He almost always appears as a large ferocious beast with horns. A demonic face is located in the middle of his torso, which contains within it the means of his defeat.
- Ghosts 'n Goblins: Astaroth is the evil and merciless ruler of Makai in his master Lucifer's stead. Extremely resistant to pain, he can shoot fireballs from both of his mouths.
- Ghouls 'n Ghosts: Having lost the throne of the Makai after his first defeat, he now watches and protects Lucifer's keep. Instead of fireballs, this time he will attack the player with his long-ranged fiery breath from both of his mouths. The player must face him two times in a row, and the second time he divides himself and corners Arthur if one of his forms is not defeated quickly enough.
- Super Ghouls 'n Ghosts: In this game, he protects Sardius and shoots laser beams and a trail of fireballs from his two mouths. He also likes to stomp on Arthur if given the chance. He will battle Arthur two times. When he is finally slain the first time, his body is possessed by an entity known as Nebiroth, the undead devil king, and he is resurrected.
- Ultimate Ghosts 'n Goblins: He is back for the final showdown! In this entry, he is called Dark Astaroth and has large black wings.
- In some older English localizations, he is often called Lucifer. Confusingly, Lucifer is actually the final boss of Ghouls 'n Ghosts.
- The spirit that possessed Astaroth's corpse in Super Ghouls 'n Ghosts, Nebiroth, was also featured in Gargoyle's Quest II.