Safari operators often speak of the "Big Five." This is a linger-longer from the blood-sport days. The phrase does not identify Africa's largest species, but rather the five most difficult/dangerous animals to hunt on foot.
Zebras and wildebeests drank the muddy water, flicked their tails, rolled in the dust, and fussed with each other. It may have just been in my head, but somewhere I could hear the soundtrack of "The Lion King" playing.