Dragons

One of the many foul beasts "created" by Melkor in his plans to destroy Middle Earth and supplant Illuvitar.
These creatures were at first land bound, but still powerful beasts. The first GLAURUNG was a fierce beast that used fire, magic, and hypnotism on his foes. Eventually they grew wings and Ancalagon, the Black was unleashed on his foes.
Following Melkor's defeat these fell beasts fled into the NORTHERN WASTES, but have returned either at the request of Sauron, or simply on their own. Most notably starting in 2570 T.A. The Plague of Dragons in the Grey Mountains.