The 10 Largest Snakes in South America

Written by Brandi Allred
Updated: May 28, 2023
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Key Points

  • The ecosystem and geography of South America make it a biodiversity hotspot.
  • Around 800 snake species inhabit South America, but only about 120 are venomous.
  • The heaviest snake in the world lives here, reaching lengths of about 20 feet and up to 550 pounds.

South America is home to the Amazon River, the Andes Mountains, and the Atacama Desert. But, this incredible continent is famous for even more than its geographic features. It is also home to some of the world’s most fascinating creatures, including mammals, birds, insects, and especially reptiles.

Approximately 800 species of snake call South America their home. Out of these species, 120 are venomous. Hiding, maybe not-so-inconspicuously, in the northern regions of the country is the largest snake in the world. Here, we’ll learn about the 10 largest snakes in South America. Number one on our list is big enough to eat a full-grown deer!

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Read on to learn more about the ten largest snakes in South America.

10. Emerald Tree Boa

Amazing Rainforest Animal: Emerald Boa Constrictor

Unlike venomous species, like king cobras and

black mambas

, emerald tree boas lack venom, relying instead on constriction.


True to its name, the emerald tree boa is bright green, with delicate white markings. Emerald tree boas grow up to six feet long. As juveniles, their coloring ranges from bright red to orange, turning green as they age. These boas live in Brazil, Peru, Venezuela, Colombia, Guiana, and Suriname. They spend nearly their entire lives in the trees, feeding on birds, reptiles, amphibians, and small mammals. 

9. Rainbow Boa

brazilian rainbow boa

As their name suggests, the

rainbow boa

has iridescent scales that reflect the colors of the rainbow.

©Kassia Marie Ott/

One of the largest snakes in South America is the rainbow boa. They grow up to six feet long and have heavy bodies designed for life on the ground. Rainbow boas live mostly in hot, humid forests, though they’re sometimes found in open lands. Their native habitat ranges from Venezuela to the Amazon River basin. Like other constrictors, they kill their prey by squeezing it to death, before swallowing it whole. Typical prey items include birds, rodents, amphibians, and reptiles.

8. Fer-de-lance


Also known as the Terciopelo, the Fer-de-lance has deadly venom and large fangs.

©David Havel/

Fer-de-lance snakes grow up to seven feet long. They’re pit vipers, which means they have heat-sensing abilities and are closely related to rattlesnakes and cottonmouths. Fer-de-lances live in northern South America, Colombia, Venezuela, Guyana, and Ecuador. When threatened, fer-de-lances famously stand their ground, and may even bite in self-defense. Their base color is light brown, with darker and lighter brown scales interspersed to create a camouflage pattern.

7. Dark Spotted Anaconda

Dark Spotted anacondas may not be the biggest anaconda out there, but they’re still one of the largest snakes in South America. These little-known snakes grow up to eight feet long, with females growing larger than males. They get their name from the dark blotches that cover most of their body, which has a base color of olive green to yellow-brown. Dark spotted anacondas frequent waterways and semi-aquatic environments.

6. Brazilian Smooth Snake

Brazlian Smooth Snake - False Water Cobra

Also known as the false water cobra, these snakes have flattened hoods like true cobras.

©Juli V/

The Brazilian smooth snake is one of the largest snakes in South America, though it’s still dwarfed by number one on our list. These snakes grow up to nine feet long and are one of the longest venomous snakes in South America. They have light tan bodies with chevron patterned dark brown to black stripes. Brazilian smooth snakes live throughout many parts of central South America and prefer humid rainforests and wetlands. Fish and frogs make up most of their diet.

5. Tiger Rat Snake

Tiger Rat Snake

Endemic to both Central and South America, the tiger

rat snake

is commonly known as the chicken snake.


Tiger rat snakes live throughout central and northern South America. They grow up to 10 feet long and lack venom. Their coloring ranges from bright yellow to dull tan with black stripes. Tiger rat snakes spend most of their lives in the trees but occasionally come to the ground to hunt. They’re opportunistic hunters and will feed on everything from small mammals to birds.

4. Boa Constrictor

What Do Boa Constrictors Eat - Boa on Tree

A popular reptile for zoos and snake enthusiasts, the

boa constrictor

comes in many different colors.

©Jan Hejda/

Boa constrictors are heavy-bodied snakes, the largest can weigh more than 100 pounds. They’ve got the length to match that girth too, with the largest boa constrictors reaching up to 13 feet long. Some grow even bigger; there are reports of boa constrictors in captivity growing up to 18 feet long. These snakes live throughout much of South America, where they spend most of their time in or around rivers or lakes. Because of their size, boa constrictors can hunt medium-sized prey, like wild pigs and deer.

3. Bushmaster

bushmaster snake curled up

The bushmaster is one of the heaviest vipers in the world, coming in just behind the Gaboon viper and

Eastern diamondback rattlesnake



Bushmasters are one of the largest snakes in South America; they can grow up to 13 feet long. They’re the longest venomous snake in the western hemisphere. As pit vipers, their mouths contain impressive, venom-delivering fangs and heat-sensing pits. Most of their bodies are copper-colored, with pale undersides and black markings. When threatened, they coil up and rattle their rattle-less tails in a warning.

2. Yellow Anaconda

Yellow Anaconda

Like all anacondas, the yellow anaconda has distinct coloring and markings. Their bodies are yellow to light brown, with dark brown circular and ovoid splotches along the back and sides.

©Chris Tefme/

The yellow anaconda is one of the largest snakes in South America. Females grow bigger than males, reaching up to 15 feet long. The largest yellow anacondas weigh over 100 pounds. These snakes spend most of their time hunting in wetlands and shallow lakes and ponds. Like other constrictors, they use their massive bulk to overpower and suffocate prey. Yellow anacondas live in Paraguay, Uruguay, Bolivia, Brazil, and Argentina. 

1. Green Anaconda

Green Anaconda Underwater

Native to most of the northern half of South America, green anacondas have long been the stuff of legend and myth.

©Vladimir Wrangel/

The green anaconda is without a doubt the largest snake in South America. At up to 20 feet long, they’re one of the longest snakes in the world. Reports of some extremely large anacondas reach as high as 33 feet, but these “monster” snakes haven’t been verified by a third-party agency.

The largest green anacondas can weigh over 150 pounds, making them the heaviest snake in the world. As their name suggests, they have a lime green color, with irregular, darker blotches.

Summary of The 10 Largest Snakes in South America

Here is a summary of the 10 largest snakes in South America and their length.

1Green Anaconda20 feet
2Yellow Anaconda15 feet
3Bushmaster13 feet
4Boa Constrictor13-18 feet
5Tiger Rat Snake10 feet
6Brazilian Smooth Snake9 feet
7Dark Spotted Anaconda8 feet
8Fer-de-Lance7 feet
9Rainbow Boa6 feet
10Emerald Tree Boa6 feet

What is the Largest Snake in the World?

Biggest Snakes: The Reticulated Python

The Reticulated Python is the largest snake in the world.


Found in the rainforests, woodlands, and grasslands of southeast Asia, reticulated pythons are the largest snakes in the world! The largest reticulated python ever recorded was discovered in 1912 and measured 32.8 feet long. The largest of these snakes held in captivity was 25 feet long and weighed around 350 pounds!

The photo featured at the top of this post is ©

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About the Author

Brandi is a professional writer by day and a fiction writer by night. Her nonfiction work focuses on animals, nature, and conservation. She holds degrees in English and Anthropology, and spends her free time writing horror, scifi, and fantasy stories.

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