Elizar
Elizar was the king of the Ratlings on Zetheda. He and his tribe rescued the Tenth Doctor and Martha Jones. With the Doctor, he discovered the Ratlings Great Orb of Refuse was actually a thousand-year-old distress beacon that was still functioning. It heralded the arrival of the Optimi race, who wanted to find the paradise world of Zetheda and destroy the Ratlings. Working with the Doctor and the Optimi leader Vlar, Elizar discovered an underground chamber with a terraforming device that turned Zetheda from a planet of waste into a paradise world. He and Vlar then made a pact: The Optimi would live in the paradise world whilst the Ratlings would remain on the surface of Zetheda. (COMIC: Waste Not)