Gantok

Gantok was a humanoid who worked for The Silence.

History
Gantok wore Viking-style attire, along with the Eye Drive worn by many servants of the Silence. 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)