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.

Green dragons are also sometimes called "earth" dragons. They usually live deep within caves, and have power over the earth. They are capable of launching boulders at high speeds, and can cause earthquakes by slamming down onto the ground.

Kurausu, or Claus, is a strange dragon. As a hatchling, he was happy and energetic. After a mysterious illness, he changed drastically. He stares blankly ahead, and doesn't do anything unless told to act. He does everything he is told to do; however, 5ilence's commands take priority over all others. Ryuka claims that he acts like his former self on the night of a full moon, but nobody else has ever seen that happen.