Kel Dors

The Kel Dor evolved on Dorin, a world with an atmosphere consisting mostly of helium and a gas that is unique to that world. As such, Kel Dor cannot breathe on planets with common nitrogen/oxygen atmospheres. Conversely, Dorin's atmosphere is toxic to most nonnative life.

On other planets, Kel Dor dwellings provide their native atmosphere (stored in large tanks). When outside, Kel Dor must wear breath masks and goggles. They can neither see nor breathe without these devices. Most Kel Dor breath masks include vocoders that amplify the wearer's speech; while their vocal cords function normally in their native atmosphere, Kel Dor must shout to provide sound in other environments. Their eyesight however, is enhanced when they are away from Dorin.