Thanos is a supervillain from Marvel Comics and the main antagonist of the Infinity Saga of the Marvel Cinematic Universe. He first appeared in the Avengers, then in Guardians of the Galaxy and Avengers: Age of Ultron, and later returned as the main antagonist of both Avengers: Infinity War and Avengers: Endgame. He is a powerful warlord known across the universe for his genocidal and ruthless tendencies. Thanos believes that the universe is in danger of collapsing upon itself as consequence of overpopulation. By harnessing the power of the Infinity Stones using the Infinity Gauntlet, Thanos hopes to "save" the universe by wiping out 50% of its inhabitants—a goal he can accomplish by activating the gauntlet with a snap of his fingers. Thanos's quest catches the attention of the Avengers, as well as other defenders of the universe such as the Guardians of the Galaxy and Captain Marvel, who band together to defeat Thanos in a battle that culminates in Avengers: Infinity War and Avengers: Endgame.