Breather

"On the distant planet of Otarius, invaders from the Birshh Dynasty have captured and enslaved the native Otarans. Pushed on by the ruthless Governor, timid Dr. Bjrork conducts horrific experiments to create a superior breed of slave. Years later, Birshh-Otaran hybrids are raised in captivity, dependent on 'breathers' - life-saving gasmasks that filter the Otarian air they, as hybrids, cannot tolerate. Two siblings, Dhrmmn and Lilli, strive to prove worthy of the Dynasty, to earn privileges for their half-breed kind."