Wyvern
Excerpts from Midgard's Noblest Beasts comprise much of this article, not because wyverns are noble beasts, but to differentiate between them and true dragons, which are innately magical and noble creatures.
Appearance
Wyverns bear some similarities to true dragons, such as a hide composed of scales. However, wyvern scales utterly lack the luster, colors, and invincibility of true dragon scales. The head of a wyvern bears no horns, unlike a dragon, and wyverns have no forelegs, as dragons do. Their forelimbs instead are their wings, on which they crawl upon their knuckles when moving over the ground. Some wyverns are said to have only forelegs and wings with no hind legs and slither like serpents. Wyverns have long, barbed tails almost like that of a scorpion, and with their stingers they can deliver venom that can slow even a mighty Jotunn. Wyverns do not grow to be even a fraction the size of dragons, but the greatest may still achieve the size of a house. They have beak-like faces and many sharp teeth.
Behavior
Wyverns behave like animals. Most are said to dwell in caverns high in mountains. They will descend to find food and return it to their nests. Some wyverns live in flocks and swarm their prey. However, they are usually scavengers, preferring to drive prey away from a large kill. They are the top scavengers in almost every environment. Wyverns cannot breathe fire and have not been known to speak, as a dragon might, though they are known to be clever.