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.

His name means "Mouse" in Japanese. He is one of the many sons of Kentaro and Kiyomi. Like his brother Kinshou, but unlike the rest of his brothers and sisters, Mausu is rather small for a horse dragon. He's a little less than two-thirds the size of most of his brothers and sisters. He is very brave for his size, and has stood up to dragons much bigger than himself (including the Hellfire Wyverns). He is however a very peaceful dragon, and prefers that everybody gets along, but when the time comes for fighting he does more than his share. He met Misaki while he was hunting; she was resting in a field of flowers. She looked so gorgeous, framed beautifully against the Peace Lillies she was resting in. He completely forgot about hunting, and instead was enthralled with the beauty before his eyes. When she awoke, she was instantly amused with the dragon standing before her. They started to spend time together, and soon were courting. Eventually they became mates, and are madly in love.