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.

Will Spirit hates the fact that he's a horse. Other dragons often mistake him for a girl, and because Will has a really bad temper, he often fights them. He is often in trouble with the leader of the cave and is forced to watch over the hatchlings and eggs (which he hates to do) as punishment. Will is very bitter. He has married the alt. vine dragon Daisy Thorn, who he met as a hatchling. She hung around him a lot, and although she annoyed him at first, he learned to love her. They married the moment she grew up. They often spend their days watching over the hatchlings while planning for their own. He adores his daughter Lily Spirit to the point where he is almost harassing her.