Vampire Dragons are members of the undead. They sustain themselves by drinking the blood of others. It is said that they are only “alive” at night, and seem dead or asleep during the day, as they cannot endure sunlight for long periods of time. Vampire Dragons can only reproduce by changing the eggs of other dragons, puncturing the shell with their fangs and injecting venom that kills the baby inside.

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.

Zero Kirryu was a Waterwalker and the child of Louise Reed and Elmer Ark. However, he was left unguarded one night and was bitten by Shizuka Shio. After a battle in his egg shell against death, he became a vampire dragon. Zero hates being a vampire and really hates Shizuka for changing him, though both of his parents and all of his siblings have accepted him as he is. He is very antisocial, and even when nighttime comes, often lays in his family's section of the cave and mopes. The only person that he interacts with besides his relatives is Yuki Kaname, a pretty young vampire who isn't aware of the fact that she's a creature of the night. He enjoys her company, and the two have awkward affections for one another.