The biggest animal in the world is the blue whale. It is one of the largest animals that has ever lived. A blue whale can grow as long as 109 feet and weigh more than 418,000 pounds. Females are a bit larger than males.
The blue whale is a baleen whale, which means it has plates in its mouth that it uses to filter out its food. It's also a rorqual whale, which means it has grooves along its throat that expand when it gulps great volumes of water. Despite its great size, the blue whale eats tiny, shrimp-like animals called krill.