Zygon

Orange aliens with the technological capacity for spaceflight and shapeshifting. They were encountered by the Fourth Doctor, Sarah Jane Smith, and Harry Sullivan at Loch Ness, Scotland. The Zygons had been trapped on Earth for hundreds of years, living near the loch, and controlled a large reptilian creature called the Skarasen which was mistaken by the locals for the mythical Loch Ness Monster.

Major appearances
Terror of the Zygons