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.

Kan en Heid created such problems at the weyr where he was hatched that they were more than happy to turn him over to Ferwe Weyr. Januset had her claws full as as she taught him when his practical jokes and teasing were appropriate and when they weren't. Today Kan en Heid is recognized for his brilliance and is respected member of the weyr in spite of his sometimes erratic and cruel behavior. (He often plays with still-living food before eating it.)

Though Kan en Heid often plays the clown there is no doubt that he is actually quite brilliant. Unfortunately he also lacks patience and is easily bored. His penchant for practical jokes has taken on a military edge as coordinates the traps and defenses set by Bluddeis and others. Expisco works well with Kan en Heid and appreciates the two-headed dragon's ability to communicate with the members of the weyr who aren't fighters.