Cold-drakes are amongst the oldest breeds of Dragon in Middle-earth and like all others are extremely scarce by the end of the Third-age. The earliest of the Dragons first apeared in the dim past of the First-age and were a manifestation of Morgoth's hatred for the works of the Valar.

The first of the dragons were flightless and had no fiery breath. Over the ages some evolved differently, developing the ability to breath fire as in the the case of Glaurung, whose descendents included true Fire-dragons who could both breath fire and fly, such as Scatha and Smaug.
There remained however in the barren wastes above the Ered Mithrin, even into the Third age, examples of the true cold-drakes, some of whom had developed the power of flight but who had no fiery breath. One such creature, although his name is forgotten in the mists of time, is famous as the slayer of the Dwarf Lord Dain I, great grandsire to Thorin Oakenshield.

Many of Durins' folk had settled in the Grey mountains after the destruction of Moria, and they built their great halls amongst those barren hills. But the drakes were still populous in those parts and the dwarves suffered much from their depredations. Finally Dain and his second son Fror were ambushed by a great Cold-drake who, sweeping down from his rocky lair slew them before the gates of their hall. This act caused the remnant of Durin's folk to abandon the Ered Mithrin, and leave the Cold-drakes to their gloomy realm.