Deep Sea Dragons, as their name suggests, spend most of their time in the darkest depths of the sea. They have a bioluminescent dorsal spine that serves to attract prey and communicate with their own kind. As with many deep sea animals, they generally eat whatever they can manage to bait. They rarely leave the ocean floor, surfacing only during breeding season. When they do choose to travel to the shallower depths, they avoid bright lights and will only come up far away from shore.

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.

A calm, graceful dragon, Rotwyrm's dark and tangled form--combined with the fact that so few know of her species--has led most of the shallow water dragons who glimpse her to believe she is the reanimated body of one of their dead. Communicating as she does with flashes of light, she has no way of understanding the garbled shrieks of terror the other ocean dwelling creatures make, and even less chance of sending a message back to them that she is harmless. Many years ago she encountered another of her race who was, like her, feared to be a corpse by the upper water dragons; the two are a fiercely devoted mated pair, and since when they are spotted they are nearly always spotted together, they were given the matching names of Rotwyrm and Wyrmrot.