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.

Loki and Mercury are frequently to blame for the chaos in Riley's clan, being that they simply cannot resist pranking the other dragons. Mercury tends to prefer a more subtle approach, but will occasionally sit back and observe when Loki uses one of his plans. Most of the time, Mercury does the planning and Loki the actual actions, but in certain situations this has been known to change.

Both heads are equally childish and are told regularly to grow up - but the two merely grin and continue on with their scheming. They have pranked all the dragons in the clan - even Azkadellia - but rarely get away clean.