Blue whales aren't just the largest creatures living today. They are the largest known animals ever to roam the face of the Earth (or rather, to ever swim the blue seas). These creatures reach a staggering 100 feet (30 meters) long, and they weigh upwards of 200 tons (181 metric tons). Still not impressed? Their tongues alone can weigh as much as an elephant.
Learn more about whales in these amazing videos below.