CHARONS

Non-human entities which developped time travel in the distant past. They were so different from all other lifeforms that during the First Time Wars, they were erased from reality by the Timelords along with the Crialans, for fear that the people of the Universe could not co-exist alongside them. In reality, humanoid minds exposed to the works of the Charon cope with it automatically by turning them into jokes. Charons were self-regenerating, and effectively immortal. They had the power to warp suns and built worlds that nothing humanoid could possibly live on. Their bodies are metadimensional and warp space-time.
Source: Doctor Who, novel Sky Pirates