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.

Nell is never far away from Mister Sweeney Todd's side- she thinks herself his accomplice, though he would rather avoid her company. Being vampires, he is the only one who does not flee at the sight of her, nor she at the sight of him.

She was laid as a carefree water dragon, but a vampire's fang turned her into a sociopath, uncaring of the means to her ends. She is very calculative and observant- she uses this to hide evidence of her and Sweeney's meals. Whether they end up in an old burial cave, a forgotten river, or down her own throat, they are never found again.