The name of the largest species of whale is the blue whale. Blue whales can reach lengths of up to 100 feet (30 meters) and can weigh as much as 200 tons or more, making them the largest animals to ever exist on Earth. They are characterized by their long, slender bodies and are known for their deep, resonant calls. Blue whales primarily feed on tiny shrimp-like animals called krill, and their populations are found in oceans around the world.