Saturn was the sixth planet of the Solar System, and is identifiable by its rings and yellow tint. In the events following Invader Dib, it was the base of the DIB Clan. It was a dark place where very few flowers grew. The planet was now made of Evil Black Crystal, which was capable of absorbing light, much like a black hole. This would cause the planet to appear and disappear from the sensors tracking it on Irk, making its orbit seem erratic and difficult to trace. For a long time, the planet remained cloaked in darkness, but some time in the future it began to emit large amounts of negative energy, indicating its presence. (Some of Dib's forces were banished to Titan as well).
Saturn appears in the episode Battle of the Planets when Zim and Dib race through its rocky rings. Saturn also makes a brief appearance in the episode The Frycook What Came from All That Space when Zim is flying back to Earth after escaping Sizz-Lorr from the planet Foodcourtia.
Soon after the creation of the new republic on the planet, there was a challenge to the peace made by Dib. Because he was human and his new queen's brother, the soon-to-be Almighty Tallest ZIM did not want to kill him, so he banished him to the planet Saturn and it became forbidden. Many years later, there was another revolt on Irk. After the battle, those who did not want to stay left Irk and ended up on Saturn where they came under the influence of the Death Phantom.