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.

Deeper Bloo claims to have gone where no other Deep-Sea dragon has gone before: Deeper.  He always makes a point of diving at least 500 feet below where his mother usually swims, even if it means ramming the ocean floor face-on.  He takes it as an opportunity to make more holes in the ocean floor, and go where no other Deep-Sea dragon has gone before, and often repeats the process.  Everyone else wonders how hard his skull must be for him not to suffer severe head trauma.