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.

Heri is the only horse dragon (and thuwed, for that matter) in HB's home. He is very stuck up because of this, often treating those who do not have the same royal ancestry or 'rarity' as himself with great disdain. He takes extra special care of his mane and hooves, making sure they are in perfect condition before he heads out. Despite his snotty attitude, deep down he realizes he is mostly valued by others for his lineage, and so he spends most of his time alone, rarely showing himself to visitors who treat him like a commoner until they discover his ancestry. He wishes people could just accept and like him for whom he is, instead of liking him merely because of his relations.