What is the heviest animal ever?

The heaviest animal ever is the blue whale (Balaenoptera musculus). Blue whales are the largest known animals to have ever existed, and they can grow up to 30 meters (98 feet) in length and weigh over 180 metric tons (200 short tons). Blue whales are found in all of the world's oceans, and they feed primarily on krill, a small shrimp-like creature.