A distinguishing feature in both sexes is the tail, which is long and similar to that of a horse. Its bright-white colour gives this animal the vernacular name of "white-tailed gnu", and also distinguishes it from the blue wildebeest, which has a black tail. The length of the tail ranges from 80 to 100 cm (31 to 39 in).
The black wildebeest has a dark brown or black coat, which is slightly paler in summer and coarser and shaggier in the winter. Calves are born with shaggy, fawn-coloured fur. Males are darker than females. They have bushy and dark-tipped manes that, as in the blue wildebeest, stick up from the back of the neck. The hairs which compose this are white or cream-coloured with dark tips. On its muzzle and under its jaw it has black bristly hair. It also has long, dark-coloured hair between its forelegs and under its belly. Other physical features include a thick neck, a plain back, and rather small and beady eyes.