Which animal is the biggest? It depends on what you measure. As of November 2026, the blue whale is the largest animal known to have ever existed. The longest confirmed ones are about 30 meters long (98 to 100 feet) and weigh up to 190 to 200 tonnes. Those are the record-holders. A typical adult blue whale weighs between 72 and 135 tonnes, much less than the record-holders. Size also depends on where a whale lives. As of November 2026, the biggest live near Antarctica. They can reach about 110 feet long. Those in the North Atlantic and North Pacific top out near 90 feet.

On land, weight and height crown different animals. As of November 2026, elephants are the heaviest living land animals, and there is no heavier animal on land today. Grown African bush elephant males stand about 3.2 meters (10.5 feet) tall at the shoulder and weigh about 6 tonnes on average, under the best conditions. As of November 2026, the polar bear is the largest land predator, though brown bears are also huge. The biggest known polar bear weighed about 1,002 kg (2,209 lb). It was a male reported in Alaska in 1960. An elephant eats about 165 to 330 pounds of plants a day.

The giraffe wins on height. As of November 2026, it is the tallest animal in the world. The tallest giraffes, the males, stand about 5.7 meters (about 19 feet) from the ground to the top of their horns; of that, the neck is 2.4 meters. A giraffe's heart is about 2 feet (0.6 meters) long and weighs about 25 pounds (11 kilograms). Its lungs can hold about 12 gallons of air. Its tongue is about 21 inches long and helps it pluck leaves from branches. Giraffes are best known for their very long neck and legs, horn-like ossicones and spotted coats.

Birds have two different records. As of November 2026, the ostrich is the biggest bird in the world, and it cannot fly. The wandering (snowy) albatross has the greatest wingspan of any living bird, up to about 3.7 meters, with an average near 3.1 meters. Aepyornis, the elephant bird of Madagascar, was a flightless bird that is now extinct. It may have been the largest bird that ever lived. An ostrich can take a stride 10 to 16 feet long. Ostriches lay the biggest eggs of any living land animal. One egg weighs about 3 pounds.

In the sea, the whale shark is the largest living fish and the largest non-cetacean animal, as of November 2026. The largest reliably recorded one was 18.8 meters long, though the true maximum length is uncertain. A whale shark's skeleton is made of thick flexible cartilage, and it has no rib cage. As of November 2026, the giant squid is the second-largest mollusc. Its maximum weight is estimated at about 275 kg for females and 150 kg for males. The ocean sunfish is shaped like half a fish. The back fin it is born with never grows, leaving a short, rounded body.

Some bigger animals no longer exist. Patagotitan walked on four legs and ate plants. Its thigh bone (femur) alone was 2.38 meters long. Paraceratherium, a giant rhino relative that lived about 34 to 23 million years ago, was one of the largest land mammals that has ever lived. As of November 2026, megalodon is among the largest and most powerful predators ever, but its fossils are fragmentary. Size estimates vary from 14.2 to 24.3 meters, with a typical length near 10.5 meters. In 2023 scientists described Perucetus colossus, a whale from the middle Eocene of Peru. Its estimated skeleton mass is greater than that of any known mammal or aquatic vertebrate.

Giants also come small. As of November 2026, the largest verified Komodo dragon was 3.13 meters long and weighed 166 kg, while wild adults typically weigh about 70 kg. Coconut crabs are the largest living land-dwelling arthropods, weighing up to 4.1 kg, as of November 2026. A giant weta, a huge cricket-like insect from New Zealand, can weigh as much as a sparrow. Goliath beetles live in the tropical forests of Africa and are among the largest insects on Earth. The goliath birdeater, a tarantula from South America, is the biggest spider by weight, as of November 2026. Its legs spread nearly a foot across. Even so, the blue whale leads the list of animals, as of November 2026.

Words to know

• tonnes: metric tons
• predator: hunting animal
• arthropods: bug-like animals
• cartilage: bendy skeleton