Which is the fastest land animal over a short sprint?

The cheetah is built entirely around acceleration. Its spine flexes so extremely that at full stretch the body works like a spring, storing and releasing energy with every stride and letting the animal cover ground far beyond its leg length. Semi-retractable claws grip like running spikes, enlarged nasal passages, heart and lungs move oxygen fast, and a long tail acts as a counterweight for sharp turns at speed. The trade-offs are severe. The cheetah is lightly built, with a small head and slender jaws, so it cannot fight for a kill and often loses one to lions or hyenas. The sprint itself lasts only around twenty seconds before the animal overheats and has to stop, panting, and if the chase goes wrong that energy is simply lost. That is why cheetahs stalk close before starting, and why success depends more on getting within range than on outright speed.

Cheetahs cannot roar; they chirp and purr, unlike lions, tigers, leopards and jaguars.