The Mercan are a race white-furred, four-eyed humanoids from the planet Zooabud. Their dense fur provides them protection from the harsh cold of their homeworld, and their eyes are adapted to specific purposes. The larger pair of eyes is used for night vision, and remain closed during the day. The smaller pair of eyes allows the Mercan to see in the glare of the sun shining off the snow, but are ineffective in the dark. The Mercan are calm and good-natured, and are tireless workers.