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.

Curyn's egg was found by the human girl, Flight, and was taken to her home in a cave near the Lake of Elgar. Growing up alongside the three other hatchlings that Flight had taken under her care with help from the Magi dragon Avedyr of the Mountains of Elgar, Curyn spent much of his time playing tag and racing around his human caregiver and her Magi dragon companion. As he grew older, Curyn was allowed to accompany Flight on her trips up the tallest Mountain of Elgar along with his White dragon "brother", Lenimen. In the mountain lived Flight's close friend and fellow dragon guardian, Ember Nuria, along with the many dragons which she cared for. During these visits Curyn would spend his time playing with the other hatchlings, particularly the Geode hatchling Crystal Nuria. Now a fully grown Horse dragon, Curyn has decided to remain with Flight and serve as her transportation to Ember's home, where he visits his friend Crystal before carrying Flight back down the mountain.