Wyverns are flying reptiles – small in comparison to a dragon, though still able to grow very large – with long, beak-like faces lined with rows of sharp teeth. They can be distinguished from young drakes by their lack of forelegs, since unlike dragons, they have only two hindlegs and use their wings as arms. Their most distinguishing characteristic is their tails, which are tipped with a large, poisonous stinger like a scorpion's. For this reason, they are sometimes grouped with chimerans.
Animalistic in behavior, wyverns are predators that like to dwell in caves along the sides of narrow mountain passes, from which they can ambush travelers by swooping down on them in flocks. They are usually scavengers, however - vicious vultures that will drive away all other takers from a fresh kill, as they are at the top of the scavenger pecking order. Wyverns cannot breathe fire and cannot speak, but their cleverness is not to be underestimated. They have been known to set up cunning ambushes.