The largest animal in the world is the blue whale, which weighs a massive 150 metric tons. Even so, it's not remotely close to being the largest organism by weight. That title goes to an organism so huge that it's estimated to weigh the equivalent of 40 blue whales. So what is this behemoth? And... where is it? Alex Rosenthal shares the story of the enormous and ancient Pando. [Directed by Lisa LaBracio, narrated by Jack Cutmore-Scott, music by AIM Creative Studios].