Such cute animal and huge at the same time. In fact, the biggest animal on the planet is the Antarctic blue whale - to live it has to eat about 3,600kg of krill per day. It can grow to 90 or more feet and weigh as much as 24 elephants - that's about 330 thousand pounds. Some of them are also the longest-lived mammals - bowhead whales can live for about 200 years and killer whales can live for 100 years and even more. Neon cursor with green Whale.