Wyvern Rider Tribes

Wyvern Rider Tribes are a group of human tribes who have mastered the art of riding wyverns as riding mounts and they are located in the southwest of the Baharuth Empire.

Background
The Wyvern Rider Tribes are located in the southwest of the Baharuth Empire. There are many canyons forming a giant array of Stela and the countless caves house a group of humans who raise Wyverns.

The Lizard Man Heroes Arc
After the situation with Shalltear Bloodfallen mind control had been resolved. Ainz acquired a Map of the New World from the Magician's Guild leader in E-Rantel. Ainz and Albedo both discussed about the various nations and localities and their capabilities.

Ainz briefly mentioned them in his discussion and while he considered them to be powerful, he deemed invading them served no real purpose for the benefit of Great Tomb of Nazarick. Not to mention that the strength and power compared between the New World and YGGDRASIL were too different to make accurate judgement. Thus, he decided not to pursue them for the time being, choosing instead to conquer the Lizardman that resided in the Great Lake.

The Magic Caster of Destroy Arc
Queen Draudillon Oriculus contemplated the possible warpath that the invading beastmen might take, after conquering her country. The wyvern riders are one such people that could be endangered should the Dragon Kingdom fall.

Trivia

 * The location's description seems to depict it to be similar to the real life Wulingyuan located in China.
 * In YGGDRASIL, flying dragons could be summoned by those with the cavalry job after reaching the late thirties' levels.