The largest animal on the planet is the blue whale (*Balaenoptera musculus*). Blue whales can grow to lengths of up to 100 feet and can weigh as much as 200 tons or more, making them the largest known animal to have ever existed. These magnificent marine mammals are filter feeders, primarily consuming small shrimp-like animals called krill. Blue whales are not only impressive for their size but also for their unique adaptations, including their loud vocalizations used for communication and navigation across vast ocean expanses. Their conservation is critical, as they were heavily hunted in the 20th century.