The Knave of Hearts was one of the deadly pawns used by the Celestial Toymaker against Steven Taylor and Dodo Chaplet when they were trapped in his realm. When not in a contest, the Knave stayed in playing card form.
He also appeared to Steven and Dodo as the Kitchen Boy and Cyril. (TV: "The Hall of Dolls" [+]Part of The Celestial Toymaker, Loading...{"namedep":"The Hall of Dolls (2)","1":"The Celestial Toymaker (TV story)"}