Azaxyr

Azaxyr was an Ice Lord of Mars and leader of the Galactic Federation troops sent to Peladon.

Biography
Azaxyr was secretly a member of a breakaway faction which desired to return to the Ice Warriors' former ways of military conquest. The faction worked for Galaxy 5 and, with Eckersley's help, tried to take over the trisilicate mines of Peladon to mine the trisillicate and send it off to Galaxy 5 instead of the Federation.

Their plan was defeated by the Third Doctor, and Azaxyr was killed when a Peladonian guard plunged his sword into the Ice Lord's stomach. (TV: The Monster of Peladon)