Ostrich

The largest bird on earth gave up flight for speed — an ostrich can hold 40 miles per hour over open ground and cover 16 feet in a single stride, using its wings as rudders to turn at full sprint. Each foot has just two toes, one of them tipped with a heavy claw that makes a backward kick powerful enough to deter a lion. And no, they don't bury their heads in the sand: what looks like it from a distance is a bird turning her eggs in a shallow nest scraped into the ground.