Halke

Commander Halke was a Sontaran with a fear of defeat. (TV: The God Complex)

Behind the scenes

 * The picture of Commander Halke is actually a promotional image of General Staal, who was played by Christopher Ryan in TV: The Sontaran Stratagem / The Poison Sky. Ryan also played Commander Stark in TV: The Pandorica Opens. This suggests that all three Sontarans were cloned from the same template.