Steve Gray

Private Steve Gray was a UNIT soldier. During Operation Blue Sky he was hypnotised by General Staal alongside his comrade Private Harris. Staal then declared him an unfit soldier. He was later used to teleport the TARDIS to the Sontaran's ship, and he was later killed by a Sontaran soldier alongside Harris after the pair had completed their objectives. (DW: The Sontaran Stratagem/The Poison Sky)

They put him in a sneaky cameo in Turn Left