This "gulphog" is an alien creature that scientists believe could conceivably exist on a planet orbiting a red star. One side of the planet would always face the star, leaving the other side in perpetual darkness. On the side that would be in permanent sunshine, immense rivers, floodplains, and forests would predominate, scientists imagine.

Gulphogs might stand 15 feet (4.6 meters) tall, have the mass of a buffalo, and the speed of a racehorse.

The illustration was made for the National Geographic Channel documentary Extraterrestrial, a look at what life on other worlds might really look like. Visit the Channel's Extraterrestrial Web site for a video excerpt, more images, and an interactive feature.

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