"Krail" was originally Eric Krailford, a young man and friend of Frank Hartley, living on Mondas. He was recruited by the Central Committee of Mondas to work as one of the "Surface teams" that worked on Mondas' propulsion engines on the surface of the planet. However, due to the freezing nature of the conditions on Mondas' surface, he was converted into a Cyberman to be able to work on the surface of Mondas, like all of the other surface teams. (AUDIO: Spare Parts) Along with Shav, Krail was killed by a handheld Cyber-weapon used by Cutler. (TV: The Tenth Planet)