Stefan was ahuman from12th centuryEarth. While inConstantinople withBarbarossa during theThird Crusade, he played a game ofdice with theCelestial Toymaker. He lost, becoming the Toymaker's first servant.

Stefan was sadistic, often enjoying carrying out the Toymaker's more cruel instructions. While theSixth Doctor was playing theGreat Game with the Toymaker inBlackpool in1986, the Doctor was able to overpower Stefan and throw him in the path of an attacking monster in the Game, which killed Stefan. (PROSE:The Nightmare Fair,AUDIO:The Nightmare Fair)