Guardians of the Galaxy
On Saturn’s moon of Titan lived a colony of Eternals, and Thanos was born as one of the last sons of the original colonists, Mentor and Sui-San. However, he was born misshapen and monstrous in comparison to the other Eternals, particularly his handsome and carefree brother, Starfox, and Thanos grew into a melancholy, brooding individual, consumed with the concept of death. More than any of his people, Thanos sought out personal power and increased strength, endowing himself with cybernetic implants until he became more powerful than any of his brethren. At some point, he was exiled from his community, although the accounts differ as to its cause. Some say it was because he committed a crime by being the first to create a weapon. Thanos himself once claimed that he vivisected his own mother in an attempt to investigate how someone consumed with death such as himself could have come into being.