The defassa waterbuck is a large, robust animal with long, shaggy hair and a brown-gray coat that emits an oily secretion from its sweat glands, which acts as a water repellent. It also has large, rounded ears and white patches above the eyes, and around the nose and mouth and throat. The common waterbuck has a conspicuous white ring encircling a dark rump, while the defassa has wide white patches on either side of the rump. Males are generally about 25% larger than the females. Only males have horns, prominently ringed and as long as 100 cm (40 in.). The horns are widely spaced and curve gracefully back and up.