What is the biggest animal in the world? It is worth noting that the largest living animals in the world today aren’t land animals, because on land they must struggle against the forces of gravity to survive, effectively limiting their size. The creatures of the oceans can grow much larger, because the buoyancy of the water offers relief from gravity’s effects, allowing them the freedom to grow to gigantic proportions. However, the list below discusses each of the largest animals in the world by type.
The Largest Animal in the World: Blue Whale (Balaenoptera musculus)

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The biggest animal in the world is the adult blue whale. They’re also the largest mammal in the world. Blue whales can weigh as much as 200 tons and grow up to 100 feet long — longer than an NBA basketball court. These animals are the heaviest known to have ever existed, surpassing any dinosaur in mass, and they are far bigger than the largest living land animal on the planet today.
The Largest Bird: Ostrich (Struthio camelus)

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We’ve already discovered the largest animal in the world, but now it’s time to take a look at the largest creature of the feathered variety.
The largest bird on Earth is the ostrich. Too big and heavy to fly, this bird is capable of running at speeds of up to 43 mph over long distances. Males can be over 9 feet tall and weigh up to 346 pounds, as much as two people. Females are usually smaller and rarely grow over 6 feet 7 inches in height.
The Largest Reptile: Saltwater Crocodile (Crocodylus porosus)

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The largest reptile in the world is the saltwater crocodile, with males reaching lengths of as much as 20 feet and weighing in at 2,370 pounds, or about twice the weight of a grizzly bear. Females are far smaller and rarely grow over 9.8 feet long. These huge crocodiles can sometimes be seen swimming quite far from shore and even prey on animals such as sharks.
The Largest Amphibian: Chinese giant salamander (Andrias davidianus)

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The Chinese giant salamander lives its entire life underwater, yet has no gills. Instead, it absorbs oxygen through its skin. This odd-looking creature is quite large, growing up to 5 feet 9 inches and weighing in at 110 pounds. At breeding time the females lay up to 500 eggs and the males act as caretakers until the young hatch.
The Largest Rodent: Capybara (Hydrochoerus hydrochaeris)

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The capybara looks a lot like a giant guinea pig, but instead of fitting into your hand this huge rodent stands 2 feet tall at the shoulders and is an impressive 4.6 feet long. Twice as big as an adult beaver, the capybara can weigh up to 143 pounds, with females being slightly heavier than males. They can live in herds of up to 100 animals, but most live in groups of 10 to 20 individuals.
These big animals resemble and act like other rodents. They are also great swimmers and are even capable of taking a nap in the water. Capybaras have unique vocalizations and get along well with other animals. They are also vegetarians who eat mostly grass and plants.
The Largest Snake: Green Anaconda (Eunectes murinus)

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In terms of mass, the largest snake in the world is the green anaconda. This huge animal has been known to weigh as much as 550 pounds, and some of these big animals have been measured up to 30 feet long. They can be up to three feet around the middle, giving them plenty of room to swallow all kinds of prey, including mammals as large as deer, fish, alligators, birds, and anything else they can catch.
The Largest Lizard: Komodo Dragon (Varanus komodoensis)

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The largest lizard on Earth is the Komodo dragon. This dangerous animal grows up to 10 feet long and typically weighs about 200 pounds. The females tend to be smaller than the males and usually reach no more than 6 feet long, about the same size as an average man. These lizards hunt large prey such as water buffalo, pigs, and deer.
The Largest Arthropod: Japanese Spider Crab (Macrocheira kaempferi)

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The arthropod family includes lobsters and crabs, spiders, scorpions, insects, and other creatures having jointed exoskeletons. The largest arthropod on record is the Japanese spider crab, which has a leg span of up to 12 feet and weighs up to 42 pounds.
The Largest Insect: Titan Beetle (Titanus giganteus)

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Titan beetles are sometimes mistaken for a form of a cockroach, but these huge South American insects are a separate species. They grow up to 6.5 inches long and weigh 3.5 ounces. They have strong mandibles that can snap a pencil and sharp claws they use for defensive purposes. Nobody knows what their larvae look like, as these have never been seen.
The Largest Fish: Whale Shark (Rhincodon typus)

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The largest fish in the world is the whale shark. This species can weigh up to 21.5 tons and grow to be 41.5 feet long. This shark lives in tropical waters above 70 degrees Fahrenheit and frequents coastlines as well as open waters. Whale sharks may look intimidating, but they are actually gentle, and many scuba divers and snorkelers seek a glimpse of them on their outings.
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