Sontaran-Prime

The  was one of the original Sontarans. He ordered that the Tenth Doctor was taken to the Sontaran war room. Once the Doctor and his companions were there, the Sontaran-Prime explained that the Sontarans had lost not only their clone worlds, but their battle forges, mega-systems and throne planets. Sontar stood still, but was on the brink of destruction, due to the Cybermen.

During an unexpected invasion, he sacrificed himself to protect the Doctor from a Cyberman coming out from a portal. (COMIC: Supremacy of the Cybermen)