Nathan (A Fix with Sontarans)

Group Marshall Nathan of the Tenth Sontaran Battle Brigade was one of two Sontarans that planned to destroy the Doctor's TARDIS with a vitrox bomb.

He and the Sontaran Turner encountered the Doctor, Tegan Jovanka and Gareth Jenkins and recognized Gareth as the Earth Defense Force leader who would defeat them in 2001. He was destroyed by Gareth when he pressed a button on the TARDIS console and shot pressured steam at the Sontarans. (DW: A Fix with Sontarans)

He greatly resembles Group Marshall Nathan of the Ninth Sontaran Battle Fleet. Given the Sontarans' penchant for reproduction through cloning, this is hardly surprising.