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 00 may be under control of the Clan of Skelokey, but being a Vampire, he has been exiled from the other dragons, and formed a semi-clan, the Clan of Singularis to keep peace with the Vampire dragons and the others.

Every so often, once an egg has been found or bred, it's chosen to be bitten and to grow up alongside the Singularis clan members. Other dragons of the cave disliked this tradition, and the High Council, or the highest ranking dragons, have taken immediate dislike to Zero's clan. When one of the members of Zero's line, or Two 02, entered the cave with a vampire egg created by an outsider, the high council attacked her, grabbed the egg, and abandoned it out of spite.

Luckily surviving, but injured both mentally and physically, Two returned to Zero and brought back the horrifying news. Struck with horror, the young leader suddenly left and vanished for days. To the council's surprise, he had gone after the egg and returned it.

Zero 00's clan was respected ever since.