Valenth

Descendants of the Companion, erosion dragons are a deep, glossy black wyvern-bodied species, with brilliant red-violet and golden stripes and accents. Their wings are broad and prehensile; on land, they are quite capable of walking with their wings and hind legs, and scrabble skillfully across cliffs and mountains.

Erosions are found throughout Valenth-- anywhere a civilization exists, in fact-- though the majority spend large amounts of time in an alternate form. All erosion are members of the Court, and as such they assist and serve political leaders throughout the world. Each dragon can take only a single form other than their true guise-- and once it is chosen, it cannot be changed.

Surprisingly, erosion dragons are completely sterile and incapable of reproduction. No one is quite sure exactly how the species is able to survive in such a situation-- or how old the current living erosions are.
Despite this, however, the species is most definitely replenishing itself... somehow.

In addition to this mystery, they also have no known breath-weapon, presumably because they are more social than militant.