The largest animal to ever grace our planet, living or extinct, is the blue whale. Blue whales have tipped the scales at 140 tons and reached 100 feet. The blue whale tongue alone can weigh as much as an elephant. Their hearts, as much as an automobile.
Blue whales reach these mind-boggling dimensions on a diet composed nearly exclusively of tiny shrimplike animals called krill. During certain times of the year, a single adult blue whale consumes about 4 tons (3.6 metric tons) of krill a day.