#2 Blue Whale (108.27 Feet)

Most of us have seen pictures of gorgeous, gigantic blue whales, but without a reference point for scale, it can be difficult to imagine just how enormous they are. Even larger than dinosaurs, the blue whale is the biggest creature ever known to have lived. They can be up to 441,000 pounds heavy. Their hearts are the size of a vehicle, and you can hear their heartbeats from two kilometers away. They are among the largest full-grown creatures when they are born.

The species nearly went extinct in the 20th century as a result of commercial whaling. Fortunately, since the worldwide ban on whaling, it has gradually recovered. Despite this, there are only under 25,000 blue whales left. These animals continue to be at risk from a variety of severe hazards, such as ship strikes and the effects of climate change.