American sergeant (The Tenth Planet)

An American sergeant was stationed at the Snowcap in Antarctica in December 1986.

He and Tito were responsible for apprehending the First Doctor, Ben Jackson and Polly Wright when they were found outside the base. He later guarded them in the tracking room and told Ben and Polly about the recent space missions.

A short time later, General Cutler sent the sergeant, Tito and Joe out to investigate the Doctor's "hut". The sergeant found he couldn't open the door, and sent Tito and Joe back inside to get a welding torch.

However, while they were gone, three Cybermen appeared. The sergeant at first thought it was Tito but soon realised that he was wrong and began to fire at them with his gun. Unaffected by the bullets, one of the Cybermen killed the sergeant with a blow to the neck. (TV: The Tenth Planet)