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.

No no not shimmery is always compared to "sha sha shimmery", because even though they are siblings they don't share the same shimmering hide. He has a plot to kill his sister when he has at least 5 other vampires as his slaves, then they will launch the attack. Till then "black as my sins" brings him eggs for him to bite then en-slave