Thanos is a fictional supervillain appearing in American comic books published by Marvel Comics. He was created by writer-artist Jim Starlin, and made his first appearance in The Invincible Iron Man #55. An alien warlord from the moon Titan, Thanos is regarded as one of the most powerful beings in the Marvel Universe. He has clashed with many heroes including the Avengers, the Guardians of the Galaxy, the Fantastic Four, and the X-Men.