Drask are large creatures, huge compared with normal desert lizards. The orcs at Mount Heldeofol have bred them for millenia and ride them like humans ride horses. They are trained to be very obedient and are rarely brought outside of Mount Heldeofol. Their bite is not strong, but they use a deadly venom. Drask bites can kill adults within hours if left untreated. Victims must get medical help as soon as possible. Drask jaws are too fragile to hunt effectively. It is believed that orcs have to gather and chop up flesh to feed to the drask to keep them alive. Drasks were originally created through black magic. Elves believe that orcs hired Balborite mage-priests to cross a dragon egg with a Jotunn lizard.
In Book 5, the elf Carnesir describes how the drask were originally created.This is the origin of the drask, according to the elves.
"Thousands of years ago, the Balborites had their own dragon riders. They trained and bred them on the island. Balborite breeders are the reason why there are black dragons today. Their breeders selectively bred for that color over hundreds of years. Eventually, they began destroying all the eggs that wouldn’t produce black dragons. They wanted a uniform species. As time passed, the Balborite religion became even more bloodthirsty and bizarre. The priests started to look for ways to strengthen their power. They used stolen elf magic to cross their black dragons with another animal. That’s how the drask lizards were created. The priests even went so far as to sell breeding pairs of this loathsome new creature to the orcs. The elves considered this an abomination. At that point, our queen intervened.” -Carnesir