Cheetah (Acinonyx jubatus) Built something like a greyhound with flawless aerodynamics, the cheetah is both the fastest mammal on earth and one of the most beautiful. Its long, graceful limbs are made for speed. The sight of a cheetah chasing prey is breathtaking. It can reach the astonishing speed of between 80 and 100 km/h. Active mostly in the morning or late afternoon, cheetahs move alone, in pairs or in groups, and several adults might collaborate to hunt a lar-ger mammal.