How big is the biggest animal on earth?

The largest animal that ever lived on Earth, and is still with us, is the Blue Whale. It averages 80 feet in length when mature, and a few blue whales measuring up to 100 feet have been found.

The Blue Whale is a 'baleen' whale, meaning that it eats tiny sea creatures by filtering them through its 'baleen'.

The mature Blue Whale may eat 4 to 8 tons a day of the tiny sea animals called, "Krill".