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.

Possessing grace comparable to that of a Skywing, Exocet is easily the most agile of the Xenowyrms of SL's cave. However, unlike his flying cousin, his moves are performed underwater, a fact he is very proud of. Many can execute aerial shows, but few can master the wavy, intricate technique of underwater acrobatics.

Exocet is a powerful master of the water. His abilities are mainly used to provide the cave with water to drink and nourish the plants, but he can create violent tsunamis when his oceans are tampered with. He, along with his Thalassa inferiors, see to the protection and preservation of the aquatic creatures. The Alpha Thalassa gets very upset when dragons throw unwanted objects into his waters, and retaliates by throwing them right back out.

Clever and proud, Exocet knows better than to stray into his comrades' domains, but if another Xenowyrm Alpha were to intrude on his grounds, they'd soon be washed ashore in a heap of seaweed, if not already drowned.