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.

Fathom Lili is one-hundred percent Deep Sea. Her name is taken from a habit acquired as a hatchling: spending hours doing little more but playing with kelp and other saltwater-based vegetation. Surfacing at night to lounge about at the top of kelp forests remains one of her favorite pastimes. Lili's only quirk seems to be her routine favoring of a Skywing male, Wyndwhisper, during breeding season. Their liaisons have resulted in sufficiently mixed-gened offspring. Content to live a simple life between raising their hatchlings, Lili takes no stand in the affairs that Wyndwhisper's distant clan concern themselves with.