Cyril

Cyril was one of the deadly pawns used by the Celestial Toymaker against Steven Taylor and Dodo Chaplet when they were trapped in his realm. He was dressed as a school boy. He acted childishly, wearing schoolboy clothing and hating losing games.

Cyril played against Steven and Dodo in TARDIS hopscotch, he used tricks such as making the floor slippery in his quest to win. He was killed when he slipped on his own trap, in his excitement at having won, he forgot it was there are fell onto the electrified floor. (DW: The Celestial Toymaker)