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.

Star and Catalyst are the mates of Hrovi Troidle. Star is a bit of a dreamer, seeking the solace of the peaceful night sky. On the other hand, Catalyst is a wild, uncontrollable dragon, who loves to play practical jokes on people. At times, they argue so much that Hrovi Troidle places a stone wall in between the two heads. Although they are so different, Star and Catalyst are a powerful team. Star normally controls the bodily functions, because he is the more logical of the two. Catalyst is the brain. He comes up with strategies for everything, from attacking prey to sleeping fitfully in the open.