Meet the Biggest Spiders in the World and Where to Find These Massive Arachnids

• The Megarachne was a prehistoric creature once thought to be the biggest spider to live on Earth with a leg span of 20 inches and a body that was 21 inches long. However, the fossil was actually a long-extinct sea scorpion. 

• Some of today’s largest spiders include: the King Baboon spider, the Face-Sized Tarantula, the Brazilian Giant Tawny Red Tarantula, the Giant Huntsman spider, and the Goliath Bird-Eating Tarantula.

• You can find all of these spiders on almost every continent worldwide in forests, deserts, caves, marshes, and grasslands.

It was considered the biggest spider ever to scuttle across the Earth. Or so scientists in Argentina thought when they uncovered the fossil of what they inevitably dubbed Megarachne — a name worthy of a classic B-movie monster.

While Megarachne would never have been big enough to go up against Godzilla, it was nothing you’d want to find under your bed either. The 300-million-year-old fossil revealed a creature with a leg span of nearly 20 inches and a body that was even longer — 21 inches.

By the early 2000s, it was determined that Megarachne was not actually a giant prehistoric spider after all, but a long-extinct sea scorpion. Current fossil evidence indicates that prehistoric spiders weren’t all that big; however, there are still species of giant spiders alive today — bigger than dinner plates, bigger than some household pets, and indeed big enough to wrap their long, hairy legs around your face if they wanted.

Despite their size, these long-legged leviathans do whatever spiders can, prowling the forests, deserts, caves, marshes, grasslands — and yes, sometimes human dwellings — on almost every continent in the world.

They may not boast dimensions quite as impressive as Megarachne, but you still wouldn’t want to find them under your bed. From the King Baboon Spider to the Goliath Bird Eating tarantula, here are the biggest spiders in the world.

Probably the biggest spider in Africa (and native to Tanzania and Kenya), the King Baboon is so named because the color and texture of the tips of its legs are said to resemble a baboon’s fingers. The leg-span of this predator can easily go up to 8 inches — more than enough to make a grown man or woman recoil if they found it in a cupboard or perched on a bathroom wall.

One of many species of tarantula on this list, the King Baboon will eat just about anything it can capture, although it mostly feeds on insects, other spiders, and occasionally small mammals or lizards (when it can get them).

King Baboons don’t have the sweetest of dispositions: They’re quick to defend themselves, have a reputation for being particularly aggressive, and are known and feared among humans for their achingly painful bite.

The venom in a King Baboon's bite won’t kill you (probably), but it’ll hurt plenty. On the other hand, it might also one day help humanity. Researchers are studying the spider’s venom to understand how it affects nerve cells once it’s introduced into a luckless victim. This research may yield new insights into novel treatments for chronic pain.

This spider is sometimes confused with the Hercules Baboon Spider (Hysterocrates hercules), a separate species of tarantula. The Hercules Baboon might score higher in the giant-spider rankings than the King, but it may well be extinct. The only known specimen, stored in the archives of London’s Natural History Museum, was found more than a century ago.

Read More: 11 Unusual Facts About the Creepy Spider — Some Have No Eyes at All

Discovered as recently as 2009, Face-Sized Tarantula is known to live in trees, but thanks to continued deforestation of its habitat, it has been increasingly found in older buildings, where it may indeed encounter more than a few startled humans.

Found in Sri Lanka and India, this memorably named spider can easily grow to 8 inches in length, sometimes a bit longer. So, yes, its legs could span your entire face if it ever decided to muckle onto you. Luckily, this tarantula isn’t much interested in preying on humans or their faces.

Like many other large spiders, our face-sized friend can prey on small rodents, birds, lizards, and snakes. Among arachnophiles, this tarantula is considered quite pretty, with some specimens sporting gorgeous patterning and a variety of colors, including pink and daffodil-yellow.

Despite the name, the Brazilian Giant Tawny Red Tarantula is native to Paraguay and Argentina, as well as Brazil. As with the other spiders on this list, the Tawny Red is indeed venomous but is said to be of a calm and retiring disposition, so your odds of getting bitten by one (especially if you just leave it alone) are pretty slim.

The Tawny Red boasts a 10-inch leg span on average, making it both big and beautiful — its russet coloring also makes it a darling among those who adore giant spiders.

Read More: Meet the Jumping Spider, the World’s Most Adorable Arachnid

The only spider in these rankings that is NOT a tarantula is the Giant Huntsman spider. Huntsman spiders are often associated with places like Australia, which seems to specialize in evolving an inordinate number of dangerous and unusual creatures. In fact, huntsman spiders are common elsewhere, especially in Asia, where the Giant Huntsman was first discovered in 2001.

While most Huntsman spiders only average a 5-inch leg span, the Giant Huntsman, which is native to Laos, has a 12-inch leg span — the biggest on this list by that metric alone. It also has a body length of about 2 inches, making it twice the size of the average Huntsman spider.

A reclusive, cave-dwelling spider, the Giant Huntsman appears to favor dark recesses and tends to prey on insects and whatever small rodents and reptiles it can nab.

While freakishly fast, a Giant Huntsman is no more dangerous than its smaller brethren — which is to say that its venom is not a major threat to humans. But if you were to measure it in terms of jump-scares, a Giant Huntsman would probably cause most humans considerable psychological dismay if you happened upon one in a dark cave — or anywhere else.

While the Giant Huntsman may be considered the largest spider by leg-span, for overall size and mass, the biggest spider in the world is the Goliath Birdeater. (Its relatives, the Pinkfoot Goliath and the Salmon Pink Birdeater are similarly outsized and often rank just behind the Goliath Birdeater in more exhaustive lists of big arachnids.)

Native to the rainforests of South America, the Goliath isn’t exactly a slouch in the leg-span department, so part of its name is well-deserved. Having said that, it doesn’t really eat birds so much; the Birdeater instead lives in a burrow on the ground, where opportunities for avian prey are somewhat scant.

Like so many massive spiders on this list, the Goliath Birdeater is an ambush predator that will lie in wait for prey to cross its path. Typically, its primary diet consists of worms and beetles, but it will also eat mice and other rodents, as well as snakes, frogs, and lizards.

It can typically reach — and occasionally exceed — 11 inches, giving the Giant Huntsman a long-legged run for its money. The Goliath’s body length, meanwhile, can measure close to 5 inches and weigh as much as 6 ounces. It’s been almost lovingly compared to the size of a small puppy, which this tarantula could probably eat if it ever stumbled upon one.

While it can give you a painful bite and has tiny, barbed hairs that can cause irritation if you grab them, the Goliath Birdeater generally poses no physical threat to humans.

However, the Goliath can’t say the same thing about us: The spider is edible and considered a delicacy in South American cuisine. Bon appetit!

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Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• Pascal and Francis Bibliographic Databases. A Giant Fossil Spiden (Megarachne Servinei) From Bajo de Veliz, Upper Carboniferous, Argentina

• National Library of Medicine. The true identity of the supposed giant fossil spider Megarachne

• PNAS. Multitarget nociceptor sensitization by a promiscuous peptide from the venom of the King Baboon spider

• Australian Museum. Spider facts

• Research Gate. Heteropoda species from limestone caves in Laos (Araneae: Sparassidae: Heteropodinae)

Before he became editor of Discover in 2012, Steve spent more than 20 years as a writer and editor, specializing in health and medicine. He began his career at a scientific, technical and medical publisher, then moved to consumer-oriented publications, where his work has appeared in Men’s Health, Men’s Journal, Prevention, Outside and dozens of other magazines and web sites.