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.

There is a guardian of the waters by a cave full of dragons. This guardian is a Deep Sea male named Tosoron. He does his job well. If a ship comes anywhere near, he'll rise up from the depths to see what its intentions are. If it's to just pass through peacefully, he'll leave them alone. If it's to go and dock anywhere near the cave, he'll scare them away. Tosoron knows the truth. He can read people's thoughts, expressions, and feelings to get the real purpose. Since a hatchling placed in the ocean, this Deep Sea has grown to be a massive dragon the humans call "The Sea Serpent". Again, this dragon does his job well and his cave is safe from sea threats.