The Mephitisians were a race of purple-skinned humanoids native to the planet Mephitis. They have four arms which were incredibly dextrous, and their black eyes were covered by clear membranes that protect them from the noxious atmosphere of the planet. They have no noses, but instead have two horn-like projections coming from the tops of their heads. These horns were sensitive to air movements and vibrations. Their mouths were protected by flaps which extend from their upper lips.