Elphon

Elphon, along with the General, was the last survivor of a very long war. Elphon was a beautiful creature, a living metal, feminine in shape, sleek and smooth like others of her kind. The Tenth Doctor's intervention at the crucial moment when Elphon was about to take the decision to set his gun to kill, and finish the conflict resulted in a truce being agreed and both parties shaking hands. This very act of contact between the last surviving male and female enabled the mix of genetic make-up needed for the next generation. (COMIC: The Last Soldier)