Slaar

Slaar was the leader of a group of Ice Warriors that took over the Moonbase in the 21st century. He planned to use T-Mat to send seed pods all over Earth which would deplete oxygen, killing the Humans and allowing the Martians to colonize the planet. He was defeated by the Doctor and was accidentally killed by one of his warriors' sonic blasts. (DW: The Seeds of Death)

A relative of Slaar, Draan, worked with the Ice Lord Falaxyr. (NA: GodEngine)