Secret Spurs

Beware the chef that tries to take these frog legs. When attacked, certain species of African frogs deploy bony spikes on the four toe tips of their hind feet. Pictured is the toe of a Central African frog with the bone claw breaking through the skin's surface. Unlike cat claws, frog claws don't slide through slits in the skin. Instead, the claw flexes downward and the sharp point breaks through the skin, ready to do its damage.

Image Courtesy: David C. Blackburn, Harvard University