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.

Rod Serling is very rarely seen by the other residents of the Dragon Cave, sometimes going many months without a sighting. As such, the Deep Sea dragon has been clouded in much speculation and many myths surround him. Some say he's secretly an aspect of the briny depths and guards the mysteries of the sea. Others are convinced he's merely the ghost of a dragon that restlessly haunts the oceans near the cave. The more skeptical bunch just believe that he is an antisocial recluse. Either way, Rod Serling is a very reserved and solemn dragon who tends to keep to himself. He doesn't appear to speak much, and when he does, his voice is rumored to be as mysterious and unearthly as his character. Truckie and Aristotyl are the only dragons that seem to associate with Rod Serling, and even they don't have much insight on why the dragon is the way he is.