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.

Mizuaru stays true to his menacing appearance. He's one of the fiercest dragons in the pack, often picking fights with wild dragons which may accidentally wander into pack territory. Even if Mizunaka and Mizunari are present to try and stop him, he can still get pretty hurt from struggling. Hence, his owner spends quite a fair amount of money treating his wounds. They still love him though, because him being territorial and protective of them shows just how much he cares.