Cheetahs are, without a doubt, the fastest creatures in the world on land. (There's probably some wickedly fast creatures in the ocean that we still don't even know about). Why would a cheetah need to be able to run so fast?

The only animal that comes in a close second to the Cheetah's amazing speed is its favorite prey, the gazelle. In order to catch up with a meal that's as swift as the wind, the cheetah had to develop the ability to run as fast, or faster than the gazelle, or face the alternative - starvation. Pretty strong motivation for practicing their wind sprints.
Fastest running animal on earth: The Cheetah
http://www.extremescience.com –
- divyas