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.

Two headed dragons are a special breed of dragons. They have two necks, two brains, two mouths, but one stomach and one main body. The two heads usually work together, but there are times when they will fight each other, attacking back and forth. They use their sharp teeth and wings to hunt large animals, and rarely eat plants. It is unknown what would happen if a two headed dragon were to mate with a one headed dragon, since it has never occurred. They only mate within their breed.

Darin and Thalis are very noble, honourable entities. They are unfailingly courteous to other dragons, and are serious almost to the point of being dour. They aren't entirely identical, of course, otherwise they'd probably bore each other into insensibility. Darin is an avid star-gazer and loves human music, often coaxing Thalis into sneaking close to human settlements during festivals and celebrations so he can listen. Thalis enjoys philosophical debates, though he can never goad Darin into one, and became fascinated by the human game of chess after witnessing a game through a window during one of Darin's musical outings.

They are both saved from being total sticks-in-the-mud by their light-hearted, laughing lifemates, Lara and Lucy.