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.

Behold, seeker of the dragon lore, Undae gena of the deep sea dragons. Her name means "wave-born" in Latin. Hardly ever are her kindred seen by human eyes as they dwell in the deeps of the ocean where the light of the day is no more than a rumour. Undae gena, though, has found that there are easier ways to hunt nearer to the surface than attracting the small fishes and fighting the krakens of the deep: At night, when the light of day does not hurt her eyes anymore, she rises to the surface, rearing her neck high so that her light shines out wide. When a ship draws near to her, hoping to find the saving glow of a lighthouse, she destroys them with a mighty crash against the bilge so that it sinks and she can prey on the sailors struggling in the water.

She is the constant mate of the deep sea dragon known as Jacikay.