As with most dragons, they are unarmored on their underside and have a week spot where the neck meets the head. Below is an average Thunder Dragon template. Actual dragons may very. The wyvern dragons of Moss are the only truly domesticated dragons known. These are the dragons used by the Dragon Knights.
Wyverns are large reptilian dragons with short necks and tails, two legs, and two wings.
They have a wing span of about twenty meters and are fifteen to twenty meters from head to tail. When ridden, a set of bit and bridle are placed on their head, and the rider sits on a mount on the wyvern's back. The wyverns of Moss are kept in large caves, which is why the Mossians have there fortresses near the mountains. The wyverns are allowed to fly free, but are trained to stay within a certain range of there caves and return when called. Wild wyverns are also common in Moss, and these should not be treated as docile or domestic ridding beast.