As a result of being a rider (and rider apprentice) for nineteen years, Aaron has almost completely finished his transformation from human to 'rider'. His ears are fairly pointed, and his face has slowly morphed from the rounder, rougher face he originally had to a sharp, elf-like one, with high cheekbones and slanted eyebrows. He retains a bit of his old features, however, and his face is noticeable 'human-tinted'. His jaw is slightly less...'fair', his face is a bit less angular, etc. The rest of his body is well-formed and toned. He isn't bulky, but he is strong enough to drag Gal a few feet, when he really puts his back into it. His face is grizzled slightly with a 'five-o'clock-shadow', and any scars or injuries he may have accrued over the years have been sealed up by magic, and are invisible. He stands tall at six feet, four inches, and is a fairly intimidating figure. He has blue eyes, navy blue, and dark brown hair, with several lighter streaks strewn throughout. He is the perfect image of a Dragon Rider teacher, according to Saphira.
Aaron is a model Rider: calm, quick-thinking, and friendly. He doesn't say as much as most, but something important can be heard every time he speaks. He gets along well with his students, regardless, and does his best to teach them properly. Most would say that he succeeded, and very few speak ill of him. He works diligently, and finishes every task he begins. He is rather intelligent, as well, and has been of great service to the Rider Order. His desire to learn, and curiosity to explore have both helped the Rider's map out the small island they live on. He and Gal have flown over most of the island, mapping the land as they go with magic, to give the Riders a fuller knowledge of their 'homeland'. Aaron rarely complains, and generally takes all responsibility for his successes and failures. Eragon once said that he was lucky to have Aaron as his Rider.
Aaron grew up in Teirm, as the son of a fairly wealthy merchant. He was raised good and proper, as his parents refused to allow him to be come 'spoiled and bratty' like the other wealthy sons and daughters. As a result, Aaron never had any close friends among his own social class. He liked talking to those of the lower classes, but was never able to see them for a long enough period of time to form friendships. The poor boy grew up fairly secluded from the rest of the world. It didn't bother him, at least not much, since he had never known anything different, but his parents were dismayed with what they had accidentally brought about. How could Aaron hope to take his father's place if he had no social skill? They didn't realize that Aaron could be quite friendly when he chose. They decided to wait until he was sixteen before they gave up completely. After all, they reasoned, there was every chance that their son would be drafted into the army, or that the whole city of Teirm would burn.
Several weeks after his sixteenth birthday, when his parents were still reeling in shock with the King's downfall, Eragon arrived in Teirm, searching for new riders. And, just like that, Eragon showed up at Aaron's front door, asking his parents about something. When they agreed, Eragon smiled warmly at Aaron, and extended his offer: come to Du Skulgrind, and learn to be a Dragon Rider. Aaron was shocked, but he accepted. After all, who could refuse the offer? Certainly not him.
Almost as soon as he arrived, Eragon pulled the silver dragon egg from nowhere, and set it in front of the boy. It hatched almost immediately, and the training of the next rider began. Aaron learned from the Eldunarí, Eragon, Saphira, Glaedr, Blödhgarm, and all manner of scrolls and books. He learned well, and although it took him three years before his teachers deemed him adequate, he took it in stride, and continued his work without faltering.
To this day, he is one of the Rider Order's most trusted individuals.