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.

Black Cat Of The Eve is a well-named dragon; not only is he convinced that he is a cat, but he is also rarely seen except on All Hallows' Eve, or Halloween as it is more often referred to. Where he goes for the rest of the year, nobody knows, but at the end of October this strange Black Dragon suddenly appears and wreaks havoc for a few nights before mysteriously disappearing again. He gets together with Rin and Len, the Dorsal Dragon siblings, as well as any willing Halloween Dragons before embarking on an activity which he calls "trick-and-treating". Unfortunately for the other dragons, this seems to consist of Black Cat and his gang pestering randomly-selected victims for food and playing pranks on them if they refuse. Another strange thing about Black Cat is the song that he sings; as has been previously mentioned, he seems to think that he is actually a cat, and says 'meow' a lot when he is singing. Nevertheless, he is now a part-time member of the Vocaloid Clan.