Gantok

Gantok was a man in the service of the Silence. He wore viking style attire, as well as an Eye Drive, as many servants of the Silence did. He was an avid player of Live Chess. He was apparently rather proud of his skill at the game and, when The Doctor had beaten him during a match, Gantok offered to pay anything to escape. He told the Doctor that Dorium Maldovar knew many things about his death and then helped him get into the Cave of Skulls, where he then turned on the Doctor. Eventually he was killed when he stepped on a booby trap that dropped him into a pit filled with skulls of The Headless Monks that proceeded to devour him. (DW: The Wedding of River Song )