Grestrenor Leader

 was part of the Grestrenor invasion fleet which wanted to annihilate the human Race. They tracked the Second Doctor and Jamie McCrimmon and wanted to render them inert. He interrogated the Second Doctor and analysed whether he was a Helt. Once UNIT discovered their plans, he decided to accelerate their plans. He wanted to save the Earth from the Helt. (AUDIO: The Annihilators)