Their horns resonate with a pure sound when struck against objects, and this can be used to send a message to its dragonkin.

The Moldruffle also has quite an unusual way of communicating with other dragons of its kind. They also have a lot of stamina and are known to travel great distances. These dragons have an aerodynamic build, making them quick and extremely agile hunters. They are quick and precise, and they can glide through strong winds in flight. They are highly intelligent and have a naturally cat-like behavior, often described as being 'wonderfully curious'. The Moldruffle is an excellent hunter, and it has a sharp, long-range vision to help spot its prey. The spikes on their crown and back became longer and sharper. Their wings are primarily blue with mauve stripes.

Titan Wing Moldruffles are mostly red, with blue patterns on their spine and tail. The Rockstomper in Dragons: Rise of Berk resembles the original design, but is purple with lilac spots. Their wings and tailfins are decorated with rows of wave-like patterns. Unlike most dragons, the digits of its wings each end in long, hooked talons. Its tail ends in a wide paddle-like fin, lined with a row of thin spikes, similar to the Shovelhelm. It has a bipedal stature, with two muscular hind legs and two shorter, stubby forelegs, each with three claws. It has a relatively wide and flat head, adorned with a crown of long, curved horns. The Moldruffle looks a lot like the Snafflefang in appearance and build. The color of the egg is a good indicator of the hatchling's color. It has a number of wave-like ridges running around its perimeter, giving it the appearance of decoratively carved wood. The Moldruffle's egg resembles an ordinary avian egg. Moldruffle description in Dragons: Rise of Berk

Moldruffle found them fresh water deep underground by using its horns as a divining rod. This Rockstomper's tracking skills came in handy when Snotlout and Hookfang landed on its island. Rockstomper description in Dragons: Rise of Berk There's no hiding from this Dragon! Rockstompers can track down anything, including their enemies in the heat of the battle. Rockstompers have a tradition of burying hidden caches of supplies under the sand, including the belongings of Vikings, much to their riders' dismay.

Skrill school of dragons