Blue wildebeest is placed in the family Bovidae, ruminant animals with cloven hooves. The generic name "Connochaetes" derives from the Greek words κόννος, kónnos, "beard", and χαίτη, khaítē, "flowing hair", "mane". The specific name "taurinus" originates from the Greek word "tauros", which means a bull or bullock. The common name "blue wildebeest" refers to the conspicuous, silvery-blue sheen of the coat, while the alternative name "gnu" originates from the name for these animals used by the Khokloi people, a native pastoralist people of southwestern Africa. Though the blue and black wildebeest are currently classified in the same genus, the latter was previously
Blue wildebeest appear long, stiff, thick, and jet black, the same colour as the tail and face. While the manes of the western and eastern white-bearded wildebeest are lank, those of the Nyassaland wildebeest and common wildebeest stick up. Scent glands, which secrete a clear oil, are present in the fore feet and are larger in males than females. In terms of skull length, the smallest subspecies of the blue wildebeest is the western white-bearded wildebeest. It is also the darkest subspecies; the eastern white-bearded wildebeest is the lightest race. Both subspecies possess a creamy white beard, whereas the beard is black