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.

Viperius has a bad tendency to bite his master's other dragons to sustain himself; so much so that he was given the nickname "Viper" by his master.  Due to his biting habits, he is forced to leave the cave at night so that he can feed, and attempt in biting eggs.  He is shown sympathy however, as he is allowed just one bite on an egg in his master's cave in an attempt to produce offspring; his master believes that company of the same species for Viperius is crucial for his overall well-being.  Due to his master trying hard to give Viperius a decent standing in the cave, the other dragons have started to show growing respect.

But only as long as he controls his appetite during the day.