The Yilltern are an insectile race native to Orcos III. Having evolved in the harsh environment of the planet, the Geonosians' society grew into a rigid caste system that defined a specific hierarchy that could not be broken: the queen, the aristocrats, and the drones. The average Yilltern was an avian humanoid with leathery skin and insectile features. Two thin wings sprouted from each shoulder, and provided the primary means of locomotion for the Yilltern. Their hands and feet ended in three digits, and their legs had two joints each. Their triangular heads were dominated by a group of thick tendrils that hung from their chins. Those Yilltern that could fly considered themselves to be superior to their earthbound brethren. Most Yilltern were simple drones, capable to doing excessive amounts of work with little or no supervision. As a people, Yilltern were efficient workers, combining their own ingenuity with vast amounts of automation to quickly produce moderate technology.