Gnu, any antelope of the South African genus Catoblepas. There are two species - C. gnu, the common, and C. gorgon, the brindled gnu. They are strange-looking animals: the neck is arched, with a hog-mane, the body and tail are not unlike those of a small pony, with deer-like limbs, and a buffalo-like hairy head, long beard, and hair between the forelegs. Both sexes bear horns. The common gnu is brownish-black, with white mane and tail. The brindled gnu, the larger species, is dun, with pale streaks. Gnus are said to be fierce, but the common species is domesticated without difficulty when taken young.