The Mountain Mauler of Montana was a famous wrestler who was taught how to fight by the First Doctor. (TV: "All Roads Lead to Rome") For some time after this meeting, the Doctor was recovering from bruised ribs, an injury sustained in their fights. (PROSE: Byzantium!) The Sixth Doctor mentioned them whilst travelling with Constance Clarke and Flip Ramon. (AUDIO: The Middle)
Charlotte Pollard talked about having invited the Mountain Mauler of Montana, Lucretia Borgia and Caligula to the TARDIS for tea when she realised that the Eighth Doctor was not listening to what she was saying. (AUDIO: Neverland)