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.

Unohana's family used to be nomadic until she was born, causing them to settle down in a roomy valley where she could swim in one of the large lakes. She often lingers at the shore, interacting with Sonea and Kusajishi. Though also one of Zaraki's nest-mates, Unohana has never had any conflict with the battle-thirsty gray dragon, probably due to the fact that she cannot get into the air to fight him.<br/>Unohana does not fight intruders, though she is often set as the last, terrible defense, hiding the eggs and hatchlings in the lake as she creates enormous waves to force back the enemy.