A blue whale is the largest animal that has ever lived on Earth, even bigger than the biggest dinosaurs. These enormous marine mammals can grow up to 100 feet long (about as long as three school buses parked end to end) and weigh as much as 200 tons (roughly 33 elephants). Despite their massive size, blue whales eat tiny shrimp-like creatures called krill, filtering thousands of pounds of them from the ocean water each day.

Blue whales live in oceans around the world, swimming through deep waters and occasionally coming to the surface to breathe through blowholes on top of their heads. When a blue whale exhales, it shoots a spectacular column of water vapor up to 30 feet into the air. They communicate with each other through deep, rumbling songs that can travel hundreds of miles underwater, far below the range of human hearing.

These magnificent creatures came dangerously close to extinction in the 1900s when hunters killed them for oil and other products. Today, they're protected by international laws, and their populations are slowly recovering. Seeing a blue whale in the wild remains one of the most awe-inspiring experiences in nature, a reminder of just how extraordinary life on our planet can be.