Elves

The Elven race dates back to ancient times, when they existed with other creatures that were bound to the land. Their appearance is that of a fair, smooth faced human with pointed ears, pale skin, thin brows and elegant facial features. The Elves are usually thin but have muscular bodies. The Elves love to sing and dance. They also have no hair anywhere on their bodies except for their head. They came from a land they called Alalea on silver ships and began living life in Alagaësia. It is rumored that Teirm is where they first landed in Alagaësia. Nowadays, they have withdrawn to Ellesméra in hopes of distancing themselves from Galbatorix. They are led by Queen Islanzadí, who succeeded King Evandar and Queen Dellanir. Queen Dellanir was the Elf Queen who argued over the creation of the Human Riders, and was succeeded by Evandar five hundred years later when she wished to study the mysteries of magic. However, she eventually let Human Riders come into existence before giving up the knotted throne. King Evandar's mate is Islanzadí, current ruler of the Elves, but Islanzadí became Queen after her mate Evandar was killed in the Elves last stand against Galbatorix in Ilirea. Arya will become Queen when her mother dies.

Dwarves

The Dwarves, who are the eldest race of them all (said to have lived for over 8 millennia), have lived in the Beor Mountains since the beginning of their race. They are described as short and stocky humans with long, dense beards who usually carry axes. They have seven toes on each foot. The Dwarves are long lived, and can live over a hundred, but are not as long lived as Elves and Dragons. They have lived in Alagaësia since they were first created, and they, along with Dragons and a few others are the true natives to the land. They believe themselves created by the Gods, and worship them wholly. Guntera, King of the Gods is a warrior and a scholar, but is moody, so they offer sacrifices to please him. They worship him because he used the bones of a giant to create the land. It is said he was born to a she-wolf at the dawn of the stars, and battled giants and monsters for a place for his kin in Alagaësia, and how he took Kilf, the goddess of rivers and seas as his mate. Urur is the master of the Heavens and the air, and his brother is the God of fire, Morgothal. The brothers loved each other they could not separate, and so Morgothal's burning Palace, which was in the air during the day and sparks from his forge glimmered at night. In the Dwarves religion, Sindri is the mother of the earth, and Helzvog is the favorite of the Dwarves Gods. After the giants were eradicated, Helzvog believed that Alagaësia should be populated, and though the other Gods disagreed, he secretly created the first Dwarf from the roots of the mountains. Learning of this, the Gods created various other things: Sindri created Humans from the soil, and Urur and Morgothal created Dragons. Guntera created the Elves, and thus the races entered the world.

Dragons

Dragons have lived in Alagaësia since ancient times. The skin of a Dragon is nearly impenetrable, though the thin membrane of their wings can be easily pierced. Their scales glitter like gems, although each Dragon only has one scale color. They also have the same eye color as their scales, and their teeth and neck spikes are usually white. They also breathe flame the color of their scales, and some could hold the flame for over an hour. They never stop growing until their death. Since they are bound to the land, they possess magical properties. They cannot willingly use their magic, except for their fire. In the war between Elves and Dragons, which started when an Elven youth hunted down and killed a Dragon like a normal animal, the Dragons banded together, and furious, attacked the Elves, leading into war. Five years into the war, an Elf found a white Dragon egg and raised it, and they stopped the war and peace arrived. In order to prevent another war, the Dragons connected their souls with the Elves, changing both races. Dragons gained the use of language and other trappings of civilization, as well as a less fierce outlook on things. Elves gained strong magic and agility and immortality. Since Humans came afterwards, the Human Riders were not affected by the Dragons as much.

Dragon Riders

Early on an elf killed a dragon mistakenly. The mistake caused a large-scale war between the two races until one day an elf named Eragon found an abandoned egg and raised the dragon. They become great friends and were able to become ambassadors between the two races. Finally peace was brought to the land and so the first Dragon Riders' purpose was simply to keep the peace between the groups.

Riders' Dragons would only hatch for Humans and Elves they believed best suited for them. Humans that are Riders experience changes over time, such as their ears growing more slanted like an Elf. Also, all become stronger of body, keener of mind, and truer of sight, whether Elf or Human. When a Dragon hatched, his Rider would form a bond with him by touching him. This touch would leave a mark, the gedwëy ignasia, on Rider’s hand. They also telepathically commune with their Dragons.

Shades

Shades are humans possessed by spirits. They're similar to sorcerers in that they both use spirits in order to accomplish magical tasks but the difference is that a sorcerer controls the spirits he uses while a Shade either gives up his mind and body to a spirit or is overpowered by one and has no control over his actions. Shades are immensely powerful, and only three beings have ever succeeded in destroying one; an elf, a Dragon Rider and Eragon. The only way a shade can be killed is to pierce their heart; otherwise they'll merely reappear elsewhere and return stronger than before. The only notable shade in Eragon is Durza. This Shade nearly killed Eragon in a city called Gil'ead but he survived by the help if his dragon and Murtagh. It is unknown whether there are any other shades in Alagaësia at the time of the book, though Paolini did say that it was possible that another shade might turn up. No new Shades were seen in Eldest, though Durza was often discussed.

Ra'zac

The Ra'zac are physically extremely powerful beings who have no grasp of magic. Ra'zac lifecycle goes as follows: when the Ra'zac are born, they are known to their parents as pupae, and they develop a roughly human exoskeleton that allows them approach their ultimate prey, humans. As described in Eldest, they have shining black skin, a humped back where future wings may be hidden, a sharp beak, a barbed purple tongue, and huge lidless eyes the size of a fist with no pupils or irises. At twenty years of age, the pupae, or Ra'zac, shed their exoskeletons and emerge as fully grown Letherblaka.