Atlas is a Titan and the son of Iapetos and Themis. He fought in the Titanomachy, supporting his parents and fellow Titans. After their defeat, he was forced to bear the weight of the sky on his back by Zeus. His brothers, Prometheus and Epimetheus, sided with Zeus and escaped penalty (although Prometheus was punished for a later transgression). Atlas is also the grandfather of the god Hermes, the son of his daughter Maia and Zeus, and Athena’s half-brother.
Less than a cameo: he only appears in a single panel in Saint Seiya: Episode G, when his mother Themis talks about him.