Tunneling dragons (Draco burrialis) are among the most infamous in the dragon world. Feared by humans and dragons alike, they are known for their brutality, strength and cruelty, not only to humans but also to members of their own species. It is for this reason they are widely considered outcasts in their own right.
The first records of tunneling dragons date back to the Babylonian Empire. They wreaked havoc with their massive horns, which were so sharp it was easy for them to bury them into the ground and tunnel deep into the earth. Their skulls had adapted to tunneling and could smash through solid rock, not to mention the bones of other dragons. Frightened by this new threat, Babylonians fled their territories, contributing to the end of the Babylonian Empire.
Eventually, the Romans arrived. Shortly after their conquest of Israel they caught wind of tunneling dragons' existence. Their rulers were not terrified but overjoyed by this news. Using brute force and immense manpower, they captured and enslaved thousands of live specimens and forced them to dig siege tunnels and trenches for use in battle.
Tunneling dragons remained in captivity for some time. As the Roman Empire continued to capture and breed other types of dragons, such as the war dragon, tunneling dragons became fiercer and more vengeful than ever. Eventually they gained enough power to overthrow their Roman masters and regain independence. Shortly after, they elected their new king, Thrasher, who was determined to wipe humans from the earth for what they did to his kind. From then on, tunneling dragons have always been extremely malevolent and brutal to all other dragons, not to mention humans.
Most tunneling dragons have very dark scales due to extensive amounts of time spent buried deep within the earth. They have incredibly sharp horns and nearly impenetrable scales but they have very bad vision and many are blind. However, their other senses have developed to superhuman levels because of this.
If a large enough tunneling dragon plunges into the earth, it can cause earthquakes and tsunamis. Governments worldwide have issued licenses to hunt tunneling dragons, although this has outraged historians and biologists who want to preserve the species.
Tunneling dragons are, as mentioned previously, extraordinarily aggressive to humans and other dragons. Great caution should be taken to avoid any of their nesting grounds and tunneling sites.