One of the last great dragons of Middle-earth, Smaug rose to prominence by laying waste to the town of Dale and capturing the Lonely Mountain (Erebor) with all of its treasure. He was already centuries old at the time, this having happened over 150 years before the events of The Hobbit. The book recounts the tale of a party of dwarves (consisting of a few of the original residents of the Lonely Mountain and their descendants) and the titular hobbit to recapture the mountain and kill the dragon. In the book, he is sometimes called Smaug the Golden or Smaug the Magnificent.

Scatha was a mighty "long-worm" of the Grey Mountains, little is known of Scatha except that he was slain by Fram son of Frumgar (an ancestor of Eorl the Young) in the early days of the Éothéod.

Ancalagon the Black is considered to have been the greatest dragon of Middle-earth, undoubtedly the largest, and is often referred to as the ‘father of the winged-drakes’. He was so large that his wings were able to blot out the light of the sun, even from afar, and his body was able to crush the volcanic Thangorodrim, the highest peaks in Beleriand. Like all other Urulóki, Ancalagon breathed fire, which was said to be hotter than any other known flame.

Glaurung is the Father of Dragons in Tolkien's legendarium, and the first of the Urulóki, the Fire-drakes of Angband. He has four legs, can breathe fire, and does not have wings. Glaurung can control and enslave Men using his mind. He is slain by Túrin Turambar.