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.

Error is the matriarch of the Grave clan, a family of Vampire dragons that specializes in nighttime "protection services." Currently, her only clients are the Calendar Dynasty, a clan of Seasonal Dragon lords. In exchange for the right to bite each client's firstborn, which may or may not be exercised, Error and her clan will fight to the death in defense of the Calendar Dynasty.  Since so many of her line were born to Calendar lords, she is also willing to let her clan members serve their mortal kin in other capacities if they wish.