The largest type of whale is the blue whale, scientifically known as Balaenoptera musculus. Blue whales can grow up to 100 feet long and weigh as much as 200 tons, making them the largest animals ever known to have lived on Earth. These majestic creatures primarily feed on small shrimp-like animals called krill, consuming up to 4 tons of krill per day during feeding seasons. Blue whales are found in oceans around the world and are known for their distinctive blue-grey coloration and long, streamlined bodies. Despite their size, blue whales are considered endangered due to past whaling practices, requiring ongoing conservation efforts.