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.

Kawaruhi has seen that his owner has a few Vampire dragons, but he feels that he is better off alone. Kawaruhi just doesn't want to bite dragons and drink their blood. He feels this is too barbaric so he is satisfied with drinking plain wild animal blood. Sadly, even separated from all his owner's dragons, he feels the need to socialize, but the dragons think he is just like other Vampire dragons and just hide their young and ready themselves to attack if necessary. Kawaruhi only has spoken to a lonely hatchling, which was lost and the Vampire dragon helped him to get home, but his parents thought that the little one was close to death, because Kawaruhi was supposed to strike any moment. Obviously, the Vampire dragon thought about the fresh blood of a little dragon, but he contained the beast inside and no one was hurt. But dragons still don't trust him and only other Vampire dragons know that he is a kind of a vegetarian Vampire dragon and shun him as well, though, for other reasons.