Koth-Kulaar
The Koth-Kulaar was a planet-eating alien from the Seventh Spiral Galaxy. It was hunted down by Space Service to an asteroid in space where it was condemned to a dimension warp. (COMIC: The Moon of Lost Hope,The Deadly Mutant)
On Earth in the 33rd century a secret council sought to track down the last of the Warp Agents (Agent 99), who had a concealed warp dimension in his chest. Tracked down by the Eleventh Doctor and returned to Earth, Agent 99 was forced by Cabal into setting the Koth-Kulaar free from its captivity and exile. In the short-lived wave of destruction the Koth-Kulaar caused (that started with the death of Cabal himself), Agent 99's last act of self sacrifice was to send it back into oblivion. (COMIC: Agent 99 / COMIC: Dimension Warp)