Vilhol

 was a cowardly Sontaran according to Strang. He did not fear death and told Leela this when she saved his life. He was the only survivor of Strang's original army, and was kept alive as Strang knew this would be a better punishment. He worked with Leela to destroy the Sontaran clone vats. He was killed by Rosato. (AUDIO: The King of Sontar)