From Tolkien Gateway
"Searching Eye" by Ted Nasmith
General Information
Other namesUrulóki
MembersGlaurung, Ancalagon, Smaug
Physical Description
DistinctionsFire-breathing; later with wings

...the fire-drakes of the North, issued from Angband's gates by night.

Fire-drakes (Quenya Urulóki) were fire breathing Dragons.

History and characteristics

The fire-drakes were the more powerful of the two fundamental divisions of dragon-kind (the other being the cold-drakes), who, as the name suggests, were able to breathe fire. Glaurung, the Father of Dragons, was the first of the species.[1] He first appeared during the late First Age, but the Urulóki were known to have survived even after the downfall of the Dark Lord Morgoth, troubling the Dwarves. Another dragon considered to be of the fire-drakes during the Elder Days was Ancalagon the Black.

Smaug, the last of the truly powerful dragons, was slain by Bard in the late Third Age.[2] We can be sure that he was not the last of the fire-drakes, though, because Gandalf refers to fire-breathing dragons in the time before the War of the Ring, nearly eighty years after Smaug's death.[3]

Other versions of the legendarium

In "The Fall of Gondolin", the first tale of the legendarium, multiple Fire-drakes are mentioned. Most of the time it is not clear if they are different from the Iron Dragons, although some of them are clearly living creatures, like the "creature of fire with Balrogs upon it" or the Fire-drake that dried the Fountain of the King.[4]