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.

Also Stuck In An Aquarium is also stuck in the aquarium together with Stuck In An Aquarium, who initially was the only deep sea dragon that was stuck in an aquarium, until, of course, Also Stuck In An Aquarium's egg was brought and placed in that aquarium in which it is now stuck as there are no oceans nearby. Taught by experience of living together with the moody Stuck In An Aquarium, Also Stuck In An Aquarium turned into a tactful, understanding dragon that knows exactly when it is time to shush up and back down. Aside from the tight quarters issue, he learned to get along well with the lady, and now they live in harmony on most days and even have children together. (Though the caretaker gives them all away for the sake of everyone's sanity and because there is really not enough room for another dragon in the said aquarium.)