9 Venomous Snakes Found in Argentina (2025)
What types of venomous snakes live in Argentina?
Due to the variety of habitats in Argentina, there are dozens of different snakes you might see. While many species are not harmful to humans, you must be careful because some types are INCREDIBLY venomous and highly dangerous. Some snakes can even cause death if the bite is not treated quickly.
In the article below, I have listed some of the most common venomous snakes you might encounter in Argentina. For each species, you will find out how to identify that snake correctly, along with pictures and interesting facts!
*If you come across any of these species, PLEASE DO NOT DISTURB! Venomous snakes are dangerous animals and should be left alone. The more you agitate them, the more likely you could get bitten. DO NOT RELY ON THIS ARTICLE to correctly identify a snake that has recently bitten you. If you have recently been bitten, GO DIRECTLY to the nearest hospital to get help and to determine if the snake is venomous.*
9 Venomous Snakes in Argentina:
#1. Brazilian Lancehead
- Bothrops moojeni
Identifying Characteristics:
- These heavy-bodied snakes are about 160-230 cm (63-91 in) long.
- They have broad, lance-shaped heads.
- The coloring is gray, brown, and olive. Body markings are a series of trapezoids or triangles in contrasting colors.
This venomous snake in Argentina is a particularly angry member of the pit viper family. Stay alert around streams! The Brazilian Lancehead likes to keep a water source nearby. At night, it lurks in lush vegetation, feeding on small mammals, birds, and amphibians.
Young Lanceheads tend to latch on to their prey, biting and not letting go until the victim is incapacitated. As they grow, they learn to release their bite to avoid injury from flailing prey. Instead, they track their victim down again as the animal succumbs to the venom.
Brazilian Lancehead venom causes immediate pain. It also thins the blood, causing dangerous internal bleeding in bite victims. In the worst cases, stroke and death are possible. Seek immediate treatment if you get bitten!
#2. Neotropical Rattlesnake
- Crotalus durissus
Also known as South American Rattlesnake, Central American Rattlesnake, Cascabel Rattlesnake, Guiana Rattlesnake, Aruba Island Rattlesnake
Identifying Characteristics:
- Adults are typically 150 cm (59 in) long on average.
- There is a prominent stripe at the base of their heads, intersecting each eye.
- Scales protrude from their body.
- They usually appear in shades of brown and gray. Sometimes, patterns of diamonds and triangles form across the body. Bellies are yellowish or white.
Neotropical Rattlesnakes in Argentina are residents of grasslands and tropical forests.
You might also find them in drier areas if a shortage of prey drives them to find food. These snakes are most active at dusk, stalking rodents and other reptiles. They’re equipped with heat-sensing pits below their eyes to track down prey.
These rattlesnakes are dangerously venomous. Left untreated, bite victims can experience muscle paralysis and difficulty breathing. In the worst cases, victims can end up with organ failure and death. Therefore, if you receive a bite from a Neotropical Rattlesnake, it’s vital to get medical help as soon as possible.
A Neotropical Rattlesnake can move with remarkable speed, but its first instinct is not to attack. To warn you, it might make a rattling sound with its tail or raise its forebody into a defensive striking posture. When this happens, it’s best to respect the warning, back away slowly, and then leave the area.
#3. Painted Lancehead
- Bothrops diporus
Identifying Characteristics:
- On average, adults are 65 cm (26 in) long, but rare specimens nearly double that length have occurred.
- Their heads are flat and lance-shaped.
- Brown and gray colors are common. You’ll also notice dark trapezoids, triangles, and blotches alternating along the body.
These venomous snakes in Argentina are well known for their intricate patterns and dangerous venom.
The Painted Lancehead is hard to spot on land because of how well it can camouflage itself. As such, it’s highly successful in catching passing frogs, lizards, and rodents.
Painted Lancheads, like other pit vipers, have special heat-sensing pits below their eyes. These pits allow them to find warm-blooded animals before they can see them. Of course, since humans are warm-blooded, they will sense you if you’re in range, too!
Great caution is advised when dealing with Painted Lanceheads. They are highly venomous, and untreated bites occasionally kill humans. If you encounter one, don’t attempt to confront or trap it because you’ll only make it angry! Back away from the snake slowly and leave the area instead.
#4. Patagonian Racer
- Philodryas patagoniensis
Also known as Patagonia Green Racer
Identifying Characteristics:
- These are slender-bodied snakes growing up to 150 cm (59 in) long.
- They have big, round pupils, rounded snouts, and prominent scaled markings from head to tail.
- Coloration is various shades of olive green or brown. Their bellies are white.
The Patagonian Racer lives in steppes and grasslands in Argentina. This reptile is technically not considered venomous to humans, but it does have toxic saliva. If you’re bitten, you might notice bruising, bleeding, or numbness around the wound site. Its fangs almost never inject enough venom to harm a human. Despite this relatively low langer, it has a nasty bite, so it’s best to observe this snake from a distance.
Juvenile Patagonian Racers prefer cold-blooded prey like frogs and lizards. Adults, on the other hand, prefer warm-blooded prey such as birds and small mammals. They spend most of their time hunting in trees during the day. At night, they retreat to land crevices to avoid Barn Owls.
This stealthy snake has a habit of startling hikers with its astounding burst of speed! It can blend almost perfectly into the forest floor or tree cover.
#5. Urutu Lancehead
- Bothrops alternatus
Also known as Urutu, Crossed Pit Viper, Wutu
Identifying Characteristics:
- Adults reach 80-120 cm (31-47 in) in length.
- Their heads are distinctly broad and lance-shaped.
- They’re brown, olive, and gray with a unique “mirrored” body pattern that can form cross-like shapes enclosed in large blotches.
Widely found in swamps and rainforests, the Urutu Lancehead is a member of the pit viper family. This highly venomous snake is drawn to the body heat of its prey using special organs in its head called “pits.” It blends into leaf litter to sneak up on unsuspecting mammals like opossums and mice.
Urutu Lancheads are short-tempered, contributing to many bites in humans. Its venom can cause serious tissue damage around the bite wound. In severe cases, amputation of the affected limb is needed. Go to a hospital immediately if you find yourself bitten by this snake!
Although they usually live far away from civilization, Urutu Lanceheads can stray into farmlands in search of prey. Sadly, farmers are often forced to kill these snakes to protect their livestock.
#6. Yarará Lancehead
- Bothrops jararaca
Also known as Jararaca, Yarará
Identifying Characteristics:
- Adults can reach lengths of 60-160 cm (24-63 in).
- Their heads are flat with sharp ridges that meet towards the front. You can spot a dark marking behind each eye, running back to the angle of the mouth.
- Coloration varies significantly. These include brown, gray, olive, and yellow with trapezoidal markings.
If you find a snake in the forests of Argentina, be extra cautious of the Yarará Lancehead. You wouldn’t want to meet this highly venomous and aggressive species. It’s responsible for many snake bites because it frequents agricultural fields while searching for food.
Lanceheads are ambush predators. They blend well on the forest floor, waiting to catch unsuspecting rodents. Juvenile Yararás use their white-colored tail tips to lure frogs and arthropods. Once they strike, they bite to inject their potent venom, which quickly kills the prey.
Astonishingly, this viper’s venom has helped save lives! Despite being deadly on its own, it was used to create the world’s first ACE inhibitor. This drug is used to treat patients with high blood pressure and certain types of heart failure.
#7. Jararacussu
- Bothrops jararacussu
Identifying Characteristics:
- Adults can grow to 2.2 m (7 ft) long.
- They have robust bodies with flat, ridged heads and greenish eyes with vertical pupils.
- Their coloring can vary from yellow to brown to black, with a pattern of dark and light scales.
The Jararacussu is one of the deadliest venomous snakes in Argentina.
Known for being highly aggressive, this snake is feared by locals and visitors alike. Its highly venomous bite results in necrosis (with amputation a very real possibility), shock, hemorrhage, and renal failure. Even after administering anti-venom, some victims succumb to respiratory and circulatory failure.
Jararacussus prefer semi-deciduous, perennial, and pine forests, as well as low swampy regions and riverbanks. If you’re in any of these areas in its range, pay special attention to where to step to avoid them.
These snakes spend the morning basking in the sun before hiding from the heat of the day. As nocturnal hunters, Jararacussus hunt small mammals, rodents, birds, lizards, frogs, and occasionally other snakes.
#8. Painted Coral snake
- Micrurus corallinus
Identifying Characteristics:
- Adults are 65–85 cm (26–33 in) long.
- They have slender bodies and small heads that are indistinct from the neck.
- Their coloring is a repeating pattern of red and black bands separated by narrow yellow bands, and they have a black head and yellow or white chin.
Although dangerous, bites from this venomous snake in Argentina are rare. They are not aggressive toward humans, and Painted Coral snake bites account for less than one percent of all cases. However, their venom is highly potent. Victims need immediate treatment to avoid progressive muscle weakness and acute respiratory failure.
These snakes are abundant in tropical deciduous and evergreen forests. They hunt other snakes, along with some amphibians and lizards. Pay special attention while hiking because Painted Coralsnakes are excellent at blending in with their environment. This is one animal you don’t want to accidentally step on!
#9. False Water Cobra
- Hydrodynastes gigas
Also known as False Cobra, Brazilian Smooth Snake, South American Water Cobra
Identifying Characteristics:
- Adults are typically 200 cm (79 in) long but occasionally up to 300 cm (118 in).
- They can flatten their necks and other sections of their bodies.
- Typical coloration is olive or brown, patterned with dark spots and bands. Undersides are lighter in color.
False Water Cobras favor the high humidity of forests and marshlands. Here, they are highly alert hunters preying on fish and amphibians in the daytime. Take note of how unpredictable these snakes can be. Some individuals are mild-mannered, while others can be quite aggressive. To be safe, it’s best to observe this species from a distance.
As their name suggests, False Water Cobras aren’t true cobras. They can, however, puff up their neck and flatten the skin to mimic a cobra’s hood. You can tell them apart because False Water Cobras can’t raise their forebodies off the ground as real cobras do.
False Water Cobras are unique because their fangs don’t hold a large amount of venom. As a result, they must repeatedly chew on their prey to incapacitate it. Consequently, bites on humans are usually not serious since we can get away before this happens. Symptoms may include swelling and bouts of muscle paralysis, so it’s still important to see a doctor.
Check out these guides to other animals found in Argentina!
-
15 COMMON Snakes Found in Argentina!
-
The 25 MOST Common Birds That Live in Argentina!
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The 21 MOST Common SPIDERS Found in Argentina!
Which of these venomous snakes have you seen before in Argentina?
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