Alien (The Night After Hallowe'en)

An alien crashed on Earth on Halloween 2010. It fed on fear, and could animate objects to generate more. The alien killed and possessed Justin. It used a perception filter to conceal its spacecraft. The ship was also powered by fear, and had it taken off, would have destroyed a 20-mile radius area. The Eleventh Doctor and Louie Rollins manage to prevent that, and destroy the alien. (WC: The Night After Hallowe'en)