John Talfryn Thomas (31 October 1922 – 4 November 1982) was a Welsh character actor from Swansea, familiar to television audiences of the 1960s and 1970s for a string of memorable supporting roles, most famously as Private Cheeseman in the BBC sitcom Dad's Army.
Before he became an actor, Thomas trained as an instrument mechanic and served in the Royal Air Force during the Second World War as a rear gunner on a Lancaster bomber, flying on multiple raids into Germany. He survived a crash in which the rest of his crew were killed, and took up amateur dramatics partly to help him recover from the experience, before training properly at the London Academy of Music and Dramatic Art.
Instantly recognisable for his protruding front teeth, which earned him the nickname "Talf the Teef," Thomas built a long career playing quirky and often seedy Welshmen. Besides Dad's Army, he appeared in two Doctor Who serials opposite Jon Pertwee, in The Avengers, The Saint, Z Cars, Coronation Street and Hi-de-Hi!, and as Tom Price in the BBC drama Survivors. He was also a regular performer on Ken Dodd's BBC radio comedy show and television programmes.
On film, Thomas appeared in Sky West and Crooked (1965) with Hayley Mills, and played Mr. Pugh in Andrew Sinclair's 1972 film adaptation of Dylan Thomas's Under Milk Wood, alongside Richard Burton, Elizabeth Taylor and Peter O'Toole. He died of a heart attack in Cardiff on 4 November 1982, four days after his sixtieth birthday.