When Water Dragons mature, they lose the ability to survive on land, entering the water permanently. They are adept swimmers and eat whatever fish are in the lake they live in. They tend to inhabit the same lake for their entire lives, although a few live in the ocean and swim all over the world.

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.

Yomigami shares in Nemoe's guarding duty of the large lake near the outskirts of the family's territory. But whereas Nemoe leans towards more violent methods, Yomigami is far more merciful. He prefers to sink rafts and boats close to the shore so that passengers do not have to swim far. If anyone is caught building a vessel near the waters edge a large wave soon destroys their hard work before they have even pulled it into the water. Humans loitering near the water's edge are doused by a strong jet of water. <br/>Not liking the taste of human flesh, Yomigami mainly sticks to eating the fish that coexist with the dragons in the lake, but the odd waterfowl has also been seen to be snapped up by his powerful jaws erupting from the lakes depths. <br/>He is on good terms with the other dragons and will speak with any of them that visit the lake. He is also fond of the family's human friends and will carry them across the water, singing sea shanties as he swims.