Megron

Megron was High Lord of Chaos and Chief of the Carions. He ruled Earth for millions of years beginning shortly after its creation, when it was still a chaotic mass of molten rock. When Megron discovered the Fourth Doctor and Sarah Jane Smith observing the planet, he became angered at the Doctor's predictions that order, specifically an atmosphere and life, would arise out of the chaos. Megron encountered the Doctor twice more at intervals millions of years apart. On their final encounter, he was banished after being defeated by the Doctor in a telepathic battle. (AUDIO: Exploration Earth)