What Is the Largest Animal on Earth?

Aerial view of a blue whaleThe blue whale is the largest animal on Earth.

The largest animal on Earth is the blue whale (Balaenoptera musculus). It is also the largest animal to have ever existed. These marine giants can weigh approximately 150 metric tons and stretch over 30 meters (98 feet) in length. There are reports of blue whales reaching lengths of 33 meters and weights of about 200 metric tons. One of the most astonishing features of the blue whale is its heart, which typically weighs about 180 kg (roughly 400 pounds). Blue whales are found in all the oceans except for the Arctic Ocean. They spend their summers in polar waters, feasting on krill, and can consume several tons of these tiny crustaceans daily. During the winter, they migrate toward the Equator to breed.

The Editors of Encyclopaedia Britannica