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.

Named for two giantesses of Norse mythology, Gjalp and Greip live up to their names as fierce, cunning fighters. They relish competition of any kind, and (usually) fight fairly in tests of strength, speed and endurance. They are seldom beaten, and it is said that if anyone should manage to defeat the duo in combat, they will be richly rewarded in gold. So far, however, no one has managed to win the sisters' treasure, though the black dragon Dark Diamond once came very close to victory. Only recently, the split brothers Thor and Mjolnir managed to defeat them, a feat they respect enormously. Their love and admiration, rather than gold, are therefore the victors' reward.