Joey the Clown

Joey the Clown 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, Joey stayed in doll form. He appeared to be mute and used an old-fashioned motor horn to attract attention or to startle people.

Joey and Clara played blind man's buff with Steven and Dodo. (TV: The Celestial Toymaker)

Behind the scenes
Bearing in mind that Cyril, the Knave of Hearts and the Kitchen Boy were all the same person, this may have been the case with Joey the Clown, the King of Hearts and Sergeant Rugg. However, this was never confirmed on-screen.