Icecanos were a type of volcano that erupted with ice instead of the more usual lava.
Spiridon had some icecanoes, because the planet's core was made of molten ice. The Daleks used the frozen temperatures to store a hibernating army of Daleks. This proved to be their downfall when the Third Doctor, with the help of a squad of Thals, flooded the hibernation chamber and the rest of the Dalek entire base with the volcano. (TV: Planet of the Daleks)