GantokGantok was the best chess player in all the galexy. He wore viking like- clothes along with the eye drive that was worn by many servants of the Silence. He was a humanoid who worked for the Silence and he took pride in winning every game of Live Chess apart from when the Doctor beat him in the "Wedding Of River Song" but would have died. So Gantok told the Doctor where Dorium was, in the leftover place of the Headless monks. He then pointed a gun at the Doctor angry for him beating him at chess, he falls into a trap and falls into a pit where many skulls eat his flesh.
Gantok was played by Mark Gatiss who is a writter and actor in Doctor Who. Who has previously done the voice of Danny Boy and played Proffesor Lazerus in the "Lazerus Experiment!