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.

Sushue is sometimes very lonely because the way she communicates with her dorsal spine has an 'accent' that makes it difficult for other Deep Sea dragons to understand her, even when she uses telepathy. She sometimes (when the loneliness weighs heavily on her mind) surfaces at night when it is dark to speak telepathically with Farkitt, a Coastal Waverunner that she knows because of their shared owner, Tender Talon. During those times she spends near the surface at night, she listens to Tender Talon and allows her head to be stroked.