Dragons are creatures with nearly unlimited life spans. They can survive for long periods of time, and no one has found a dragon that has died of old age. Adolescence 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. Once they hit adolescence, hatchlings change quickly, maturing to their full forms in only 2 years.

Dragons don't communicate with each other verbally, but they will growl to scare off predators and frighten prey. Young dragons will emit an extremely high-pitched squeal when they are frightened. To communicate, they use telepathy with each other and to speak to other creatures.

When water dragons mature, they lose their legs and 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.

Nereus was discovered as an egg by sheer luck, bobbing up and down in the frigid waters of Lake Ontario toward the turbulent waters preceding Niagara Falls. Nobody knows how he managed to slip into the water and survive that long in chill waters, but the female human who became his just happened to be visiting the falls and noticed him with her hawk eyes, and snatched him before a terrible fate was met. She transported him to a great, still lake near the mountain cave where her other dragons resided, and there he has remained quite happy, content to take his human and the hatchlings for swims under the sun.