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.

Red dragons are similar to typical story book dragons. They shoot flames, can fly, etc. However, they aren't evil creatures as depicted in myths and won't go around raiding castles, killing knights, or kidnapping princesses. They live in a variety of habitats, from forests to coastlines to abandoned castles, usually in warm climates, and eat whatever living creatures they can find.

With a vicious temper and fiery blast furnace breath, Kirijo is a reminder of why so many myths of dragons being violent killers first started. Given the job of guarding the families hoard deep within the bowels of the cave, Kirijo rarely ventures outside, but when she does, the jewels and gold pieces that have become embedded in her scales may fall free, leaving the hatchlings to scurry around and reclaim the lost treasure.

No human prince, or knight, or monk, no matter how daring or full of wit may he be, has ever succeeded in stealing from Kirijo. Only one human has escaped her hatred and anger towards their race, the human female that found Kirijo as a tiny hatchling and saved her from death, with less than a day to live.

Kirijo is surprising gentle with this particular human, as well as the newborn hatchlings, whom she fusses over and will often let them play with her wings and tail.