Dinosaurs were huge, but they were not the biggest. As of November 2026, the blue whale is the biggest animal that has ever lived, bigger than any dinosaur known. Patagotitan, a huge plant-eating dinosaur from Argentina, is one of the largest dinosaurs known. A blue whale can be about 100 feet long and can weigh 150 to 200 tons. That is many times more than an elephant, the biggest land animal.

A blue whale eats tiny shrimp-like animals called krill. It feeds by taking in a huge mouthful of water and krill. It pushes the water out through baleen plates, which trap the krill. A blue whale can eat about 4 tons of krill in a single day. A newborn calf is already about 23 to 25 feet long.

The sperm whale is the biggest of the toothed whales, as of November 2026. Males grow to about 52 feet long. A sperm whale dives deep to hunt squid. Dives routinely reach 2,000 feet and can last 45 minutes. Giant squid have the largest eyes of any living animal except perhaps the colossal squid, about 10 to 11 inches across. The longest giant squid reported were about 59 to 60 feet long, but most that people find are 35 to 45 feet. Much of that length is arms and tentacles.

As of November 2026, the whale shark is the biggest fish in the sea. It is a shark, which is a fish, not a whale. Its mouth can be 1.5 meters (about 5 feet) wide, with hundreds of rows of tiny teeth. It does not chew with them. It filter-feeds, taking small food out of the water. It eats mostly plankton and small fish.

On land, the elephant is the heaviest living animal, as of November 2026. A big male African elephant can weigh about 6 tons. An elephant eats about 165 to 330 pounds of plants a day. Blue whales are among the loudest animals on the planet, and a blue whale lives about 80 to 90 years.

Words to know

• Patagotitan: giant dinosaur
• baleen: whale strainer
• tentacles: long arms
• plankton: tiny sea life