Described by the Tenth Doctor as "a fine and noble race who built an empire out of snow", the Ice Warriors were a species of reptiles from the planet Mars. They were twice encountered by the Second Doctor – first, when their crashed ship was thawed out of a glacier during a future Earth ice age, and then when they tried to take over the Earth’s trans-mat system. On both occasions, the Warriors were dangerous aggressors. In a subsequent meeting with the Third Doctor on Peladon, the Ice Warriors had renounced violence and entered the Galactic Federation. However their warlike nature could not be kept under control for long…