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.

Birthday's parents were two simple horse dragons, who loved each other and only wanted one thing: a kid. When Birthday was born on his mothers birthday, (and his own...) He was named Birthday Wish. He doesn't mind his strange name, but sometimes wishes it was something manlier—like John.