Black Dragons are warriors. They are strong and capable in battles of force, but also ample magic users, capable of devastating opponents with their spells. Their bright eyes give them excellent night vision, which is why they generally hunt during the night.

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.

Ossien lives up to the description of his breed; belligerent and vicious, he is apt to challenge any other dragon in the cave, and each and every time he attacks with what seems like intent to rip the other dragon apart. Only two dragons in the cave are capable of turning his rage away, Sapeis and Plaeria. Ossien, having grown beside Plaeria from egghood, has never shown any hint of aggression toward the peaceable white, and is often seen relaxing by Plaeria's side on the cliff face, watching whatever weather passes through the area. They are as close as brothers, but it is uncertain whether they understand such a human concept.