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.

Mint colored dragons are the most peaceful of all dragons; they only eat plants unless they scavenge meat from an already dead animal. They also have no ways to attack others or defend themselves. They are much smaller than other forms of dragons since they only double in size when they mature. Mint dragons are unable to use magic and cannot fly since they lack wings. Their looks have given rise to the common insult of calling dragons "large lizards."

Eurymedon is one of the two Cabeiri, while he uses his intellect; his brother often favors to think of himself as their protector. Which is just as well, for Eurymedon is thought the weaker of the two and so more often attacked. These two brothers are strange, for though their lineage is nothing to scoff at; their size often labels them as unimpressive. Yet they aspire all the same to be as grand as their ancestry proves they can be.

Both accompany Eosphoros-Hesperos in his journeys after he encounters them attempting to find the source of the underground river guarded by LadonUnsleeping.