Dragons
Dragons were sentient creatures that roamed freely in the land of Alagaësia. They were the mounts and life-long companions of the Dragon Riders. Apart from werecats, spirits, Nïdhwal, and Lethrblaka, dragons were the only known intelligent non-humanoid species.
There were only four known dragons left in Alagaësia during the Rider War: Shruikan, Saphira, Thorn, Firnen, (though Saphira, Firnen, and Thorn were merely still eggs) and Glaedr. He was the only other dragon known to be alive at the start of the Rider War, then he was killed by Galbatorix(through Murtagh and Thorn) and then resided in his Eldunarí which was in Eragon's possession.
The dragons of Alagaësia were reptilian, with scales, sharp teeth, bat-like membraned wings. and a tongue that covered with hooked barbs.They could develop the ability to breathe fire as they matured. Their color varied from dragon to dragon, and there appeared to be some variation in features between different colored dragons, but all dragon colors were the same species. For example, Saphira, a blue dragon, possesses four cheek spikes, slightly curved horns, and two forehead spikes while Thorn, a red dragon, had wide, crescent-shaped horns, and two cheek spikes. Glaedr, who was gold, had six cheek spines, crooked horns, and a beard. According to Brom, dragons could grow to be "larger than most houses" and that some older dragons could be confused with large hills. They were connected to the land in strange ways, that sometimes even they could not control. This is shown when Saphira touched Zar'roc with her muzzle, and when she turned Brom's grave to diamond.
Dragon eggs tended to be the same color as the dragon's scales, as did the color of their Rider's magic. Their scales were very strong, capable of deflecting arrows, even on the underbelly. The wings were the weakest part on their body, composed of only a thin membrane of flesh. (Saphira often had holes punched in them once her wards failed.) Females tend to be more aggressive, vain, and stronger than males, as Saphira often calls herself the "most beautiful creature in all of Alagaësia", as well as attacking Glaedr when he opposes to mate with her. Glaedr himself said that in the wild, the "females were so formidable". All dragons had matching color for their eyes and hide and possessed long, barbed tongues. All dragons ate meat, especially deer and other ungulates. The dragons were similar to other creatures, namely the Nïdhwalar and the Fanghur who were said by Glaedr to be "cousins of the dragons". The Lethrblaka were also said to resemble the dragons somewhat in their appearance.
Dragons hatched from eggs. It is unclear if all dragons were the same size at birth as the size of their eggs varied. When dragons reached about six months old, they gained the ability to breathe fire. Predators by nature, they hunted large animals, with an occasional fish or fowl and some plants, such as Fireweed, which eased bad breath and indigestion.
Dragons started to mate when they were young. They were unfading and did not die, unless by wounds in battle or by sickness. There was no limit to a dragon's size, as they grew continuously. Brom said that the most ancient dragons could be confused for hills or small mountains because of their size; a dragon sized directly correlated to the size of the Eldunari. The largest known dragon was Raugmar the Black. Once dragons grew large, they spent most of their time asleep in a dream stage.
