The 40 Most Extreme Animals on the Planet

To cut it in the animal kingdom, you have to be tough—really tough. From withstanding brutal climates to fending off ferocious predators, surviving in the wild is no small feat. But a few cunning creatures have developed interesting traits and habits to stay in the game. Here are 40 of the most genetically gifted, physically freakish, and just all-around coolest animals in the world.  BY