Boulder

Boulder Class dragons are tough and associated with the earth. They can eat rocks, and despite that their wings are smaller compared to their entire body, they are able to fly as fast and as high as most other dragons can. The Gronckle, Whispering Death, and the Screaming Death are members of this class.

Gronckle
It is relentless, stubborn, and direct like a compact bereserk rhino, yet very loyal to its rider

Whispering Death
Whispering Deaths are extremely deadly, like most other dragons, and able to chew their victims after they are swallowed, using its many rows of rotating teeth. They tend to dwell in underground tunnels that they burrow themselves, resurfacing to attack any oncoming enemy/prey.

Screaming Death
The Screaming Death appears to be a mutated, albino Whispering Death. It is white in color, has large red eyes, a longer and more massive body and tail than a normal Whispering Death.