Originating from a single species that thrived in ancient times, Xenowyrms have become an incredibly diverse breed whose appearances vary depending on their habitats. Each Xenowyrm subspecies is heavily reliant on the power of a different type of mana, making them powerful magic users. Thalassas are a unique variety of Xenowyrm in that they are the only subspecies known to dwell in marine environments. Their porous skin and slender build are perfectly suited for the aquatic terrain, but they can only survive for short periods of time on land. Powerful users of water magic, they can create large waves and alter currents with a simple thought.

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.

Artemia monica is a kindly young thalassa living amongst the waters of the island the Fossil Waverunners call home. He pals around with the Coral Pygmy Sangomon and it's said that she is the only dragon that the aggressive little wyvern won't attack on sight.

Artemia has made a solid living by swimming and following the coastal waverunner scouts as they fly look for boats that are in need of guidance or rescue, and Artemia provides the muscle when a situation gets out of hand. He once grabbed a large fishing vessel by the fishnets and dragged it out of the path of an approaching tsunami.

The Thalassa's long beautiful body is almost as impressive as his huge shimmering sailfin which sailors in the region have learned to recognize. The Sailors now pay the dragons generously with offerings of fish to ensure safe passage. Which Artemia shares with the waverunners. It's also known that sealife such as sharks will follow boats, and Artemia often makes a meal out of these creatures as well.