Bright-Breasted Wyverns are a breed of dragon easily recognized by their bright red markings. They are a small breed, only the size of a full-grown man. However, they have developed poisonous barbs on their feet to make up for their size. Their coloration is used to warn off potential predators of the danger, and is also used to attract mates. They are very social, and can often be seen preening in large groups.

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.

Matteo is very loyal to both the dragons he befriends and his tamer. His markings are brighter than many males of his species, but he is also smaller as a trade-off. He doesn't let his size hold him back, however, and will fiercely defend any of his friends from much bigger dragons that pose a threat. Matteo doesn't have a clearly defined sleep schedule; sometimes he seems to be crepuscular, other times diurnal, and sometimes he is asleep all day and wakes only at night.