J. R. R. Tolkien's Middle-earth legendarium features dragons based on those of European legend, but going beyond them in having personalities of their own, such as the wily Smaug, who has features of both Fafnir and the Beowulf dragon.
Dragons appear in the early stories of The Book of Lost Tales, including the mechanical war-dragons of The Fall of Gondolin. Tolkien went on to create Smaug, a powerful and terrifying adversary, in The Hobbit; dragons are only mentioned in passing in The Lord of the Rings.
Tolkien's conception of the dragon has been adopted both in games loosely based on his Middle-earth writings, and by other fantasy authors. Several taxa have been named after Tolkien's dragons, including both extinct and living species. Several taxa, including girdled lizards, shield bugs, and ants, carry the name Smaug.
Dragons are already present in The Book of Lost Tales. Tolkien had been fascinated with dragons since childhood.[T 1] As well as "dragon", Tolkien called them "drake" (from Old English draca, in turn from Latin draco and Greek δράκων), and "worm" (from Old English wyrm, "serpent", "dragon").[T 2] Tolkien named four dragons in his Middle-earth writings. Like the Old Norse dragon Fafnir, they are able to speak, and can be subtle of speech.[1][2] In the earliest drafts of "The Fall of Gondolin", the Lost Tale that is the basis for The Silmarillion, the Dark Lord Morgoth (here called Melkor) sends mechanical war-machines in the form of dragons against the city; some serve as transport for Orcs. These do not appear in the published Silmarillion, edited by Christopher Tolkien, in which real dragons attack the city. As in the later conception of the dragons in the Legendarium, the winged dragons had not yet been devised by Morgoth at the time of the Fall of Gondolin. The first winged dragons appeared at the same time as Ancalagon the Black.[T 2] In the late Third Age, the dragons bred in the Northern Waste and Withered Heath north of the Grey Mountains.[T 3]
In Tolkien's works, dragons are quadrupedal, and may be either flightless, like Glaurung, or winged, like Smaug. Winged dragons first appeared during the War of Wrath, the battle that ended the First Age.[T 4] Some dragons, known as "Fire-drakes" ("Urulóki" in Quenya), are capable of breathing fire. It is not entirely clear whether the "Urulóki" were only the first dragons such as Glaurung that could breathe fire but were wingless, or to any dragon that could breathe fire, and thus include Smaug.[T 5] In Appendix A of The Lord of the Rings, Tolkien mentions that Dáin I, King of the Dwarves, and his son Frór were killed by a "Cold-drake", prompting their people to leave the Grey Mountains.[T 6] It is commonly assumed that this indicates a dragon which could not breathe fire. Dragon-fire (even that of Ancalagon the Black) is described as not being hot enough to melt the One Ring; however, four of the Dwarven Rings are consumed by Dragon-fire.[T 7] All Tolkien's dragons share a love of treasure (especially gold), subtle intelligence, immense cunning, great physical strength, and a hypnotic power called "dragon-spell". They are extremely powerful and dangerous but mature very slowly. Because of this, Melkor's first attempts to use them against his enemies failed, as they were not yet powerful enough to be useful in battle.[T 4]
Tolkien named only four dragons in his Middle-earth writings. Another, Chrysophylax Dives, appears in Farmer Giles of Ham, a story separate from the Middle-earth corpus. Chrysophylax is a fire-breathing dragon, described as "cunning, inquisitive, greedy, well-armoured, but not over bold".[T 8]