Horse Dragons have equine-shaped bodies and hooves instead of claws, which allow them to be fast runners. They specialize in running takeoffs, which are quicker than taking off from a stand-still. Horse dragons are able to stalk their prey from the ground then quickly execute an aerial attack for the kill.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Exhilarario, or "Rio" is a very quiet and almost shy dragon. She is very insightful, and will only speak if she believes her words will be beneficial to the conversation. The first dragon of Shadow's clan, she was found along with two other eggs, and was the only one to survive due to Shadow's inexperience in raising dragon eggs.  After Rio stumbled upon Niveus' egg, she took it to Shadow and convinced her to help her raise the tiny dragon that would hatch from it, thus beginning the clan. Shadow however, didn't want much to do with the dragon clan, and only brings in abandoned eggs and orphan hatchlings. As such Rio, who viewed the human as something akin to a mother, misses her quite frequently. When Shadow does Show up, everyone can always expect Rio to be the first one trotting up to greet her.