You may be looking for the Sontaran of the same name.

Colonel Stark was an officer in the US army. Like many Americans at the time, he was vehemently anti-communist, and even allied with the Viperox in exhange for a chance to destroy the Soviet Union. He first met the Tenth Doctor, Cassie Rice and Jimmy Stalkingwolf in 1958 when he defended them from a Viperox, blowing it up with a missile. He arrested the trio, claiming they had seen too much, and attempted to wipe their minds. Once the Doctor had escaped, Stark was warned by the Viperox leader, Azlok, that he had better not mess up. He later found the Doctor, Cassie and Jimmy with another one of his enemies, Rivesh Mantilax, and attempted to arrest him. He tried to kill the Doctor, whom he claimed was a communist, but was convinced to turn on Lord Azlok and abandon his ambitions to devastate Russia. (TV: Dreamland)

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