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.

Running in the River, or Running as the members of his cave refer to him as was the first dragon to be documented by the proprietor of the cave.  In spite of being confined by his nature as a water dragon to the underground lake inside the cave, he is the leader of the dragons in the cave, and thus is looked to for wisdom and advice.  However, the squabbles between the other members of the cave occasionally annoy him, and thus he travels through the underground river that connects the underground cave to the outside world to escape from the realities of cave life.  All the same, he enjoys the life he now leads as the leader of the cave and the ability he has to regulate the activity of the other members of his cave.