Answer:
Birds are the world's fastest animals, especially the Swift and the Peregrine falcon. But, here's a break down of fastest depending on land, sea, and air.
Land: the cheetah (70 mph / 113 km)
Air: Swifts (106 mph /171 km). Peregrine falcons can fly at 90 mph / 171 km and dive 200 mph / 322 km
Water: Sailfish ( 70 mph / 113 km)