1. Blue Whale (Balaenoptera musculus): The blue whale is the largest animal currently living on Earth. They can reach up to 100 feet in length and weigh up to 200 tons.
2. Argentinosaurus huinculensis: This dinosaur, which lived in South America during the Late Cretaceous period, is estimated to have been up to 115 feet long and weighed up to 100 tons.
While the Argentinosaurus was larger in length, the blue whale is slightly heavier on average. So, depending on how you measure "largest," either animal could be considered the winner.