Zeus was an Olympian and the leader of his race.
After the Olympian Prometheus stole life spores and spread them across the galaxy to create life, Zeus became angry and banished him to an unknown planet, to be chained to a mountain for the rest of his existence. Zeus believed that the life spores should only be used once, to produce peace-loving creatures. (COMIC: The Life Bringer)
Arrival of the Doctor Edit
Once Prometheus returned with the Fourth Doctor and K9 to the planet Olympus, Zeus sent Aphrodite to bring them to him. Prometheus tried to reason with Zeus that people were good but Zeus mentioned that most of them knew how to hate, steal, kill, and start wars; they had poisoned the universe with their actions. He had Prometheus sent to the confinement rooms whilst the Doctor and K9 were sent to Asclepius to be studied.
After the Doctor, K9, and Prometheus escaped, Zeus showed his wrath by appearing in a gigantic form in the clouds. He sought to stop them by attacking them with massive amounts of electricity. However, once they got into the TARDIS, Zeus wasn't able to destroy the ship with his powers. (COMIC: The Life Bringer)