Fastest Mammal (land)
Cheetahs can run up to 70 miles per hour.

Fastest Mammal (water)
Dall porpoises can swim up to 35 miles per hour.

Fastest Bird (sky)
Peregrine falcons can dive toward the earth at more than 200 miles per hour.

Fastest Bird (land)
North African ostriches are both the fastest bird on land—running up to 45 miles per hour—and the biggest, weighing in at 345 pounds.

Fastest Fish
Sailfish can swim up to 68 miles per hour.

http://nationalzoo.si.edu/Animals/AnimalRecords/