Light (Ghost Light)

Light was a member of an unidentified alien species that had the power to teleport. He travelled through the universe making a catalogue of life.

Biography
Light was a traveller of the universe and took it upon himself to catalogue all organic matter. He took Nimrod, a member of the Neanderthal race, as a specimen for his catalogue. Redvers Fenn-Cooper claimed to have seen a dazzling light while hunting in Africa, noting that it had wings and other features similar to that of Light. Light had been asleep for centuries while in his spaceship, and while he had, life had evolved. Josiah Samuel Smith was Light's survey, run under the auspices of another alien on Light's ship, Control. Josiah changed to mimic the different life on Earth and in doing so, left behind Husks.

Light was angry that his catalogue was ruined due to life evolving, so he decided to destroy all organic matter so that it would stop changing and his catalogue would be complete. He killed a maid and took her apart in order to see how her body worked. He killed Inspector Mackenzie, turning him into soup, and turned Lady Pritchard and her daughter Gwendoline to stone. The Seventh Doctor showed Light that he himself was evolving and, realising that he was wrong, dispersed. (DW: Ghost Light)

Appearance
Light's appearance was majestic and imposing, which wildly contrasted with his bewildered, frustrated behaviour, doddering speech pattern and screeching timbre. Light's form depended on his environment, and so when he awoke he appeared as a human in an alien robe who glowed with a yellow light. The Seventh Doctor explained to Ace that he moved at the speed of thought. (DW: Ghost Light)