A bird as big as a fighter plane. A snake the size of a school bus. A shark 100 times heavier than an average great white. Before the time of humans, our planet was ruled by a land of giants, with fish that could swallow you whole and land predators tall enough to peek into the top floor of the White House. But which of these mega-monsters was the largest of them all? Join us as we reveal the Top 10 biggest beasts to walk the Earth, swim the seas, and soar the skies.