The Worms of Morgoth
Dates: First recorded in c. I 265
Types: Cold-drakes, Fire-drakes (the Urulóki), Long-worms, Were-worms
Other Names: Worms

Mighty reptilian creatures who ranked among the most feared of the servants of the Dark Lord. Of the origins of dragons, no tale tells; the first of them to be seen was Glaurung, Father of Dragons, who first issued from Angband in the middle of the First Age. After Glaurung came many others to strike fear into Elves and Men for the next three ages; among them were Ancalagon the first winged dragon, Scatha who dwelt in the cold northern wastes, and Smaug, last of the great dragons.

The cold-drakes could neither fly nor breath fire. The Urulóki, e.g. Glaurung, could breathe fire but lacked the ability to fly. Dragons are sometimes referred to as Worms. Two different kinds of "worms" are mentioned in the works of Tolkien; the Long-worms and the Were-worms. Long-worms (e.g. Scatha) lived in the far north in the elder days. Not much is known about were-worms.

Dragons have powers of intelligence and speech, and many are also able to cast the dragon-spell, a bewildering confusion that affects any who gaze into the eye of the creature. Dragons are clever and cunning creatures, almost as deadly using their tongue to lure their victims closer, as when they use their raw power and firebreathing mouth to kill.

The dragons were not destroyed at the end of the Third Age; some are said to have survived to our own time, but the great worms and drakes of the Elder Days are no more.

Mightiest of the winged Dragons
Dates: First seen in the War of Wrath in c. I 583, in which he was slain.
Titles: The Black

The mightiest of Morgoth's winged dragons, loosed from Angband against the host of the Valar at the end of the War of Wrath. Even that mighty army was driven back by the onset of Ancalagon and his vassals, but Eärendil came through the sky in Vingilot to do battle with the dragon armada, and he was aided by Thorondor and the Eagles. They fought for twenty-four hours, until Eärendil at last slew Ancalagon, who fell on the mountains of Thangorodrim and destroyed them in his ruin. This marked the end of Morgoth´s rule.

Golden Father of Dragons
Dates: First seen in I 265. Slain by Turin Turambar in I 498
Titles: Father of Dragons, The Golden, The Great Worm, Worm of Morgoth

Glaurung (Glorund) was the first of the Dragons, and one of the greatest. He first issued from Angband in 265 (First Age), but not being fully grown at that time, the Noldor under Fingon were able to drive him back.

In the Dagor Bragollach and the Nirnaeth Arnoediad, Glaurung was in the vanguard of Morgoth's forces, and having grown to his full power, he wreaked great destruction on those battlefields. He destroyed large parts of the Elf-lands Ered Wethrin, Dorthonion and Nargothrond. In the Nirnaeth, he was driven back to Angband by the heavily armoured Dwarves, though their lord Azaghâl was slain in that battle.

Glaurung led the assault by Morgoth on Nargothrond, and there came across Túrin Turambar for the first time. He dwelt in the ruined halls of Finrod Felagund for a while, but came forth at last to seek Túrin. He was slain by Túrin's black sword Gurthang in the Forest of Brethil.

A mighty Long-worm of the Grey Mountains
Dates: very uncertain, Probably slain in about the year III 2000
Division: Long-worms

Scatha was the mightiest dragon north of the Grey mountains during the third age. Of his life little is known, except that he was slain by Fram son of Frumgar (an ancestor of Eorl the Young) in the early days of the Eothéod.
His recovered hoard was the subject of great dispute between the Men of the Eothéod and the Dwarves of that region, who claimed the hoard as their own. Fram rebuked their claim, and sent them the teeth of the dragon, with the words, "Jewels such as these you will not match in your treasuries, for they are hard to come by." Thereafter there was war between the Éothéod and the Dwarves, and Fram was said to have been slain by them.
However this dispute was resolved (we are not told), it seems that Fram's people retained at least some of the hoard, and brought it south with them when they settled in Rohan. The horn that Eowyn gave to Merry Brandybuck after the War of the Rings(many hundred years later) was said to come from it.

The Dragon of Erebor
Dates: Presumably bred in Angband in the late First Age, slain III 2941
Division: Fire-drakes
Titles: Dragon of Erebor, The Golden, The Magnificent

Smaug was the last of the great fire-drakes, and said to be the greatest dragon of his time. At some time during the twenty-eight century of the Third Age, he came to hear of the immense wealth held by the Dwarves of Erebor. Where he came from we do not know for certain, but in the year III 2770 he descended in fire on the Lonely Mountain, destroying the Dwarf-kingdom and the nearby township of Dale.

Gathering together the treasures of the Dwarves, he formed himself an immense bed of gold and jewels and settled within the ruined halls of Erebor. Slowly the years and decades passed, until the people of the Long Lake to the south had almost forgotten the Dragon of Erebor and Smaug imagined himself unassailable.

Then, one day in the October of III 2941, one hundred and seventy-one years after his arrival in Erebor, Smaug awoke to find his treasure disturbed. Of all that mountain of wealth, he noticed with rage that a single two-handled cup had been taken. He could not have imagined that the loss of that cup signalled his own imminent downfall; Thorin, the heir of the King under the Mountain that Smaug had driven from his halls those many years before, had returned to reclaim his kingdom. With him came Bilbo Baggins, a hobbit with a magical Ring with which he had invisibly removed that single cup from Smaug's treasure.

In his anger, the dragon flew from his halls, scorching and breaking the mountainside. Thorin, Bilbo and their companions were sealed in a hidden tunnel, and at last the frustrated Smaug gave up his attack on the mountain. Realizing that they must have had help from Lake-town to the south, he set out to punish the Men of the Lake instead.
That was to be Smaug's last flight. Bilbo had managed to discover an open patch in the dragon's armour, and word of this had been carried to Lake-town. In particular, it reached the heir of another of Smaug's victims; Bard, the descendant of Girion of Dale. Bard shot Smaug with an arrow, and though Lake-town was devastated in his attack and fall, the dragon was defeated. In years to come, beneath the waters of the lake his mighty bones could be seen, and the jewels that had lined his hide: the last remains of the greatest dragon of his age.