Skip to Content

18 Most Dangerous Rainforest Animals

Rainforests are found in South America, India, Southeast Asia, and Africa. They teem with life, and some of those species only occur in the rainforests. They are home to some very dangerous animals. Here’s some info on 18 of the most dangerous animals that live in the rainforest.

The 18 most dangerous animals in the rainforests are:

Reticulated pythonGreen anacondaKrait
King CobraFer-de-LanceCoral snake
Black caimanElectric eelRed-bellied piranha
Poison dart frogBull sharkBullet Ant
Brazilian Wandering spiderAmazonian Giant centipedeJaguar
Tiger Vampire batMosquito

This article explores these dangerous animals, looking at what makes them dangerous and gives some interesting facts and information about each animal…

Dangerous Snakes In Rainforests

The rainforests in various regions of the world have some of the world’s largest and most venomous snakes.  Snakes can be divided into two primary groups: 

  1. Venomous snakes – They kill by injecting venom with a bite.
  2. Non-venomous snakes – They are usually constrictors that kill their prey by restricting blood flow and oxygen to vital organs. Cardiac arrest or brain death occurs very rapidly. In some cases, scientists measured cardiac arrest occurring in thirty seconds.

Reticulated Pythons

Reticulated pythons are the longest snakes globally, growing to over twenty feet (6.25 meters). Some specimens have been measured at over thirty-two feet (10 meters). Reticulated pythons are constrictors that are found in the rainforests of south-east Asia. 

Note: This post may contain affiliate links which will take you to online retailers that sell products and services. If you click on one and buy something, I may earn from qualifying purchases. See my Affiliate Disclosure for more details.

Most reticulated pythons will avoid interactions with humans, but large ones have been known to attack and eat people. Local tribal people who live and work in the rainforests are most at risk.

Green Anacondas

Green anacondas live in the Amazon rainforest. Although they are not as long as a reticulated python, they are the world’s heaviest snakes. They are dark green with black markings. Their markings allow them to blend into the damp undergrowth where they live. Green anacondas are often found in shallow streams or swampy areas of the forest. They ambush animals that come to drink, pulling the prey down into the water and drowning the animal.

On land, the anaconda uses constriction to kill prey. Green anacondas do not usually attack humans but, there have been reports of green anacondas attacking and killing humans. The problem arises when they become habituated to people who live in the rainforest. The people may then be viewed as potential prey by large anacondas.


Kraits are extremely venomous snakes of the cobra family. They are nocturnal hunters that live in the Asian rainforests. Base colors may be black, brown, blue, and yellow with white or black bands. Kraits live close to human settlements in the rainforests, and bites usually occur when people are sleeping on the floor of their huts.

Kraits have potent neurotoxic venom, resulting in neuromuscular paralysis, respiratory failure, and cardiac arrest. Many people are unaware they have been bitten, which causes a delay in seeking medical intervention. Kraits have tiny teeth, and there is minimal pain at the bite site. 

King Cobras

King cobras hold the title of the world’s longest, venomous snake. They can grow to twelve to eighteen feet long and expand their necks into a hood when threatened. King cobras can lift three to four feet of their body off the ground, chasing prey or threats for quite a long way in this manner. King cobras acquired their name because a large part of their diet is made up of other snakes.

Generally, king cobras will try to escape from interactions with humans. If cornered, they will inflate their hoods and lift the front part of the body and chase the person. Female king cobras guard their nests and will attack without provocation. King cobras have neurotoxic venom. They are found in the rainforests of Africa, East Asia, and India. King cobras have a very loud, low hiss, which sounds more like a growl. 


A fer-de-lance viper is one of the most dangerous animals in the rainforest

Fer-de-lance is a snake of the viper family, which is found in the South American rainforests. Its average size ranges from four to six feet, and females are usually longer than males. These are nocturnal snakes that are unpredictable due to nervousness. The fer-de-lance puffs up its body to appear larger and will shake its tail to scare off predators. Its life span is approximately twenty years, and it ranges in size from 1.8 meters to 2.4 meters.

They have broad flat heads and may be brown or black. 50 mg of fer-de-lance venom is enough to kill an adult human, and the fer-de-lance injects 105 mg in one bite. These snakes are responsible for killing more humans than any other snake in South America. It has hemotoxic and cytotoxic venom.

Coral Snakes

Coral snakes are brightly colored, small snakes which inhabit the rainforests of South America and Asia. They are relatively small snakes with a maximum length of three feet. They have extremely potent venom, but they have short fangs and need to bite for a more extended period or ‘chew’ on the victim to inject enough venom. They like to lie under leaf piles in the rainforest and may bite if stepped on. They have neurotoxic venom, which causes muscle paralysis. Death occurs from respiratory failure.

Black Caimans

Black caimans are the largest alligators and are found in the South American rainforests. They easily grow to 15 feet in length and are fearsome apex predators. They spend a large proportion of their time in rivers and attack any animal or human that ventures close to the river. They are strong swimmers and can move very fast when lunging at prey on the river bank. They have a strong bite, which they use to grip prey to drag into the river to drown.

Electric Eel

Electric eels are not really eels but rather belong to the knife-fish family. They release electric charges up to 860 volts into the water when threatened. This causes collapse, and some victims drown in shallow water as a result of being shocked. The electric shock may also cause respiratory failure. Research has shown that electric eels sometimes hunt in packs increasing the amount of electric charge in the water. Their electric charge can even stun large caimans. The eels are most active at dusk and dawn.

Red-Bellied Piranhas

The majority of piranhas do not attack humans, but the exception to this is the red-bellied piranha. They usually feed on fish and crustaceans in the river. In drought or where other prey is not plentiful, they will launch a group attack on any animal or human which ventures into the river. They have razor-sharp triangular teeth with powerful jaws that can take the flesh off a large animal in a few minutes. They only occur in the Amazon rainforest and are a much-feared predator.

Poison Dart Frogs

Poison dart frogs are highly colored frogs that live in the Amazon rainforest. These tiny frogs (2,5 cm – 5 cm) have iridescent colors that warn off predators. The golden dart frog (Phyllobates terribilis) is the most poisonous of all the poison dart frogs and has enough venom on its skin to kill ten adult humans.

These frogs feed on ants, crickets, termites, beetles, and centipedes. The poison dart frog obtains its poison from the insects that it eats, so each frog has a different composition to its poison, depending on its diet. The glands on the frog’s skin store the toxin. Frogs kept in captivity do not have toxins if their diet does not include poisonous insects or centipedes.

Bull Sharks

Bull sharks (also known as Zambezi sharks) are a surprising animal to find in the rainforest. They are unusual sharks in that they can live in both fresh water and saltwater, having been found up to 2500 meters up rivers. They get their name from their stout, thick bodies, blunt heads, and habit of head butting prey. 

A bull shark is classed as one of the worlds five most dangerous sharks

Bull sharks are unpredictable, aggressive sharks that are fearless when attacking prey. They grow to seven to ten feet and weigh up to five hundred pounds.  Their attack method is to ram the prey with their heads and then bite repeatedly. Bull sharks are classed among the world’s five most dangerous sharks. They prefer to hunt in shallow, murky waters, making it hard to spot them coming.

Bullet Ants

Bullet ants (Paraponera clavate) are found in the rainforests in South America. They are 0,7 inches to 1,2 inches (18 – 30 mm) in length with a reddish-black club shape to the bodies. They are predatory ants with an extremely potent sting. They live in colonies of several hundred ants, usually situated at the base of trees. They are prevalent in the rainforest, and so the chances of encountering them are high.  They are not naturally aggressive but defend their nests vigorously. 

Although bullet ants will not kill you if you are a healthy adult, you will probably prefer to be dead if they sting you. They have the highest pain rating of any sting in the world. The sting is so painful it is likened to being shot, hence the name, bullet ants. The pain persists for 24 hours. The toxin (poneratoxin) is a neurotoxin causing paralysis.

Other stings symptoms include swollen glands, edema ( fluid retention), tachycardia (increased heart rate), and blood in the feces. The stings often cause victims to shake uncontrollably for several hours afterward. Victims with an allergy or heart condition may die from the stings.

Scientists estimate that if a victim were stung by 2,250 ants, he would die. Astoundingly one of the Amazonian tribes uses these ants in rituals for men to become accepted as adults. It makes you glad that you don’t belong to that tribe!

Brazilian Wandering Spider

The Brazilian Wandering Spider is also known as Banana Spiders as they are often found in banana leaves. Their bodies are two inches (5 cm) long, and their leg span is approximately six inches (15 – 18 cm). They are hairy, brown, or grey and may have black spots.

Their hunting technique is to ambush or directly attack prey, and they do not build webs. Their usual diet is insects, small reptiles, amphibians, mice, and other spiders. When threatened, they warn aggressors by raising their first two pairs of legs to show the scarlet hair around their fangs. Females are bigger than males and often eat the males after mating.

Brazilian Wandering Spiders have a complex venom that attacks the neuromuscular system. The first signs after a bite are extreme burning pain at the bite site and sweating. This is followed by vertigo, cardiac disturbances, vomiting, gastrointestinal distress, salivation, blurred vision, shock, and convulsions.  There is anti-venom available, and if bitten, the victim should seek medical help immediately. Bites are more dangerous to children.   

Amazonian Giant Centipede

The Amazonian Giant Centipede is indeed a giant with a length of twelve inches(30 cm). Their bodies are brown, red, yellow, or black, and their legs are yellow. They have fangs that are modified appendages which they use to inject venom.

These centipedes have a potent venom which attacks the respiratory, cardiovascular and nervous system of victims. It can kill a mouse much larger than itself in thirty seconds. There are records of these centipedes killing humans. Their venom is so fatal because of one particular toxin, which disrupts the channels responsible for maintaining the cells’ potassium balance. Without this channel operating, the brain, heart, lungs, and other body systems shut down completely.     


Jaguars are the third biggest wild cat and are found in the Amazon rainforest.  Jaguars are opportunistic hunters and will eat anything they can find. In the rainforests, their prey includes capybaras, armadillos, birds, fish, monkeys, iguanas, and even tapir and the feared caimans. They will hunt at night and during the day.

Jaguars have immense strength and can carry heavier prey than themselves up steep inclines or into trees. They have powerful jaws; some scientists claim their bite is the strongest of all wild cats. Jaguars ambush prey by attacking from the undergrowth or trees. They spring onto the prey, biting into the back of the skull or the junction of the head and neck.

A jaguar has immense strength as well as strong canine teeth

Their strong canine teeth easily crush the skulls of their prey, penetrating deeply into the brain. Generally, jaguars avoid contact with people, but there are reports of unprovoked attacks on people. Most attacks occur when people inadvertently scare or challenge the jaguar or wander too close to a litter of jaguar kittens.


Tigers are the largest wild cats, with males tipping the scales at 660 pounds. They are found in the south-east Asian and Indian rainforests. Tigers attack prey by leaping at the throat or neck, and the prey suffocates or the neck breaks.

Tigers kill more people than any other wild cat, mostly because villages exist deep within the jungles, and so there is more exposure to humans. Generally, old or injured tigers begin hunting people once they realize the ease with which they can do this. Historians have noted after times of epidemics or floods when human bodies are not adequately disposed of; tigers may get a taste for human flesh after eating corpses. 

Vampire Bats

There are three species of vampire bats, but only the common vampire bat feeds on mammals. They congregate in colonies which can range in number from a hundred to a thousand. The bats’ sharp fangs are used to cut a wound into the animal, and then they lap the blood from the wound. They inject anti-coagulants and a form of local anesthetic so that the victim will not feel them feeding.

People report waking up to find their sheets covered in blood and have no idea what happened. It is often difficult to stop the wound from bleeding, and infection is common. The bats can also transmit the hantavirus and rabies to their victims.  Aside from the disease risk, most humans would probably develop profound night terrors if they were to find a bat feeding on them.


Mosquitoes are, surprisingly, the most dangerous creature in the rainforest. They exist in swarms in every rainforest, and avoiding being bitten can be challenging. More than a million people die of mosquito-borne diseases each year. Only female mosquitoes bite mammals to get a blood meal.

The mosquito inserts her proboscis into the skin. It injects enzymes that prevent blood clotting while at the same time sucking up the blood. Mosquitoes carry several different diseases, which they transmit when they feed on a person. The most prevalent ones in the rainforest are malaria, dengue fever, and yellow fever.


Rainforests are fascinating places to explore, but it is wise to take precautions to avoid the potentially dangerous creatures that live there. It is easy to step on a snake, spider, or centipede accidentally. It would be wise to have first aid training and knowledge of the closest medical centers. Rainforest rivers are home to many dangerous animals and should be approached with care. A knowledgeable guide is probably best to ensure you do not run into trouble.

You Might Also Like: