Bison horns - Your bison horns, unlike deer and elk antlers, are made of a substance similar to hair. They are also slow-growing and permanent. They grow in yearly "rings" which indicate age.

Spear-nosed bat ears - Hungry for a late-night snack? With spear-nosed bat ears, you can find food—even in the dark. Just listen for echos—they can lead you to a delicious insect.

Sand tiger shark teeth - Your smile is deadly. Your spiky sand tiger shark teeth are perfect for gripping fish and other slippery prey.

Grevy's zebra hoofs - Get up and running. Grevy's zebras can stand up just six minutes after being born and can run after just 45 minutes. How long did it take you to learn to walk?

Chilean flamingo legs - ou'd think flamingos stand on one leg by locking their knees. But those are actually their ankles. They stand like that to conserve energy. How long can you stand on one leg?

Monarch butterfly wings - Your monarch butterfly wings can beat five times per second. Can you flap your arms five times in one second?