Dragons, dragons... and the greatest of them all

Dragons are the oldest and by far the most terrifying evil creatures that have appeared in Middle-Earth. They were divided into two strains: the royal tribe, fire-breathing dragons, and a minor race, cold dragons, whose power was only strength. Dragons had scales, long tails, were enourmous and their thirst for evil was uncommon even among the other forces of darkness. They were also terribly intelligent, which added to greed and cruelty, was making them very dangerous beasts. They always were my favorite race of Arda, and everytime they appeared - be in The Hobbit or other books of Legendarium - I clapped my hands and prepared for literary feast.

In the Old Age, there were two greatest dragons - deadly Ancalagon the Black, a Death from Above and wyrm-like Glaurung, the "first of all".

There were at least two great dragons in the Third Age: Skat of the Gray Mountains and Smaug the Golden, who took the Lonely Mountain into his possession and became the King Under the Mountain, terror of Dale and horror of all races.

He took Mountain with Erebor - his main target - filled with dwarven gold, which bold miners couldn't forget him... and that's how the twilight of dragons in Middle-earth began...