The yierka is an omnivorous reptilian quadruped native to the Sea of Fire. Their hides are thick and they possess natural armor in the form of plates to protect from sandstorms. They are used as mounts and beasts of burden by the Tehir tribes that populate the desert, and are able to traverse areas of the desert that are too inhospitable for camels. They are said to have the manners of a camel and the attitude of a perpetually angry feline. Their use requires a dominant handler and they are the preferred mount of Tehir warriors.
Yierka-riders wear tall, knee-high boots for protection, often equipped with a large spur. The yierka-spur, a fist weapon mounted with one to three spikes, evolved from the foot gear of the yierka-rider.