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.

Gray dragons are the masters of the skies. They are excellent fliers and land only to rest and eat. In addition, they have full control of the weather. They are very hot-tempered and easily angered. They will attack any human that bothers them, conjuring strong winds and dangerous lightning.

Sanada Genichirou is the one of the cave the others have to look out for. He sometimes gets angry quickly, and is not very patient. He is, however, very kind to his master, and tries to be good around her. He spends his time flying at high altitudes, and, using his control over the weather, he will often make it rain or snow for his master to enjoy. He has a soft spot for Brenna Danielle, and keeps her from harm. He hopes they can be good friends.