Top 11 Most Dangerous Animals You May Find in Costa Rica

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Sorry, but there are some darn dangerous animals in Costa Rica. This is one of the world’s most biodiverse countries, remember? Slithering snakes meet bullish sharks and surreptitious spiders in the wilds. They reside in fish-teeming marine reserves and cloud forests and lush jungles alike, spreading between the Central American Pacific Ocean and the Caribbean coast. This list details just a few of the creatures you might want to bear in mind as you come to travel the land of Pura Vida.

Fer de Lance

Fer de Lance
Image by Katrin Schulz from Pixabay

The Fer de Lance reigns as the single most dangerous snake in Central America. That’s down to the stats – it bites more people than any other serpent species in the region. The reason? It’s considered to be very unpredictable when faced with human contact. Some will slither away quickly. Others will attack without warning. That’s not great news when you factor in that the Fer de Lance has a debilitating venom that can cause gastrointestinal bleeding, internal hemorrhaging and local necrosis that can entirely destroy limbs and organs. The snakes live primarily in hot, humid, lowland areas below 2,000 meters above sea level.   

Eyelash viper

eyelash pit viper
Image by Werner Eckhard from Pixabay

The eyelash viper is an eye-catching snake if there ever was one. Many of the species are colored a deep, daffodil yellow. What’s more, just as the name implies, they have long, protruding eyelashes over the tops of both blinkers. Right at home in the misty coast jungles of lovely Costa Rica, these guys can be spotted on low-hanging branches, often near ravines and creeks. They’re not considered aggressive but do possess a strong hemotoxin venom that can lead to over-clotting of blood inside the arteries. Eyelash pit vipers are deceptively small, and a lot of victims disregard a bite because the fangs themselves do little damage. Don’t do that. Medical attention is a must if you’ve crossed paths with one of these serpents in the backcountry.

Coral snake

coral snake
Image by mgrpowerlifting from Pixabay

There’s bad news and good news when it comes to the coral snake. The bad news is that there’s no question these guys are up there with the most dangerous animals in Costa Rica – herpetologists think they have one of the deadliest venoms in the whole world. The good news is that they tend to be a lot less aggressive than many of the other serpents on this list. There are actually four different types inhabiting this corner of Central America. They all have an alternating black, red and yellow tricolor pattern in common. Coral snakes survive on a diet of small amphibians and lizards and are rarely seen by humans thanks to a penchant for living in dense jungle and rainforest.


bushmaster snake
Photo credit: Esquilo @ Wikimedia

The bushmaster has the Latin genus name Lachesis, after the Fate of Greek mythology who determined the duration of human life. That should offer a clue to just how dangerous they are. One of the biggest pit vipers anywhere on the planet, these sliders can clock up lengths of up to three meters from snout to tail. They also possess some of the biggest fangs in the snake world and use them to inject record levels of venom into prey. Thankfully, the bushmaster is really rare. It lives solely in the remote jungles and rainforests that roll off the Costa Rican coastlines, both on the Atlantic and Pacific oceans. Aside from the colossal size, look for alternating brown and black markings going down the back, along with a spiny tail cap that is sometimes used to warn off attackers.

Poison dart frog

yellow poison dart frog
The Golden Poisonous Frog is the most deadly animal in the world | Image by jggrz from Pixabay

Once used by indigenous tribes across Central and South America to load up their projectiles, this curious genus of amphibians has a deserved place among the most dangerous animals in Costa Rica. That’s not because it has a potent attack, or for its fang or bite. It’s simply down to the sheer potency of the stuff that’s secreted on its skin. You only really need to touch it to feel the effects. The golden poison frog (phyllobates terribilis) is known to have the strongest poison of all. It’s a mix of alkaloids that can induce heart palpitations and seizures. Each frog is thought to carry enough of the stuff to kill over 15 fully grown adult humans.

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Black widows

Black Widow Spider
Image by jgiammatteo from Pixabay

Black widows are actually some of the most common venomous spiders in the world. They reside all over the Americas, from north to south. Feared for their debilitating bite, they now have a near mythic status. The truth is that black widow bites are rarely fatal. They can cause death in humans, but that’s often in vulnerable people, older victims, or the very young. We certainly wouldn’t put them up there with the likes of Costa Rica’s venomous snakes, for example. That said, they’re worth watching out for when you tread through the jungle paths of this stunning country.

Brazilian wandering spiders

Brazilian wandering spider
Photo credit: berniedup @

Get ready for it – the Brazilian wandering spider is considered more deadly than the infamous black widow. With a venom that causes paroxysms and spasms, muscle deterioration and fever-like symptoms, there are loads of reasons why you wouldn’t want a nibble from one of these guys. They live in the forests of Costa Rica and South America but are also called banana spiders on account of their penchant for residing on our favorite yellow fruit. The wanderers can grow up to seven inches in length and have a similar look to a tarantula – hairy legs, brow thorax, fangs at the front.

American crocodiles


There are oodles and oodles of these mighty beasts in Costa Rica. They love the tropical lowlands of the country, and often live alongside riverbanks, in muddy swamps and in lightly forested areas with plenty of water. With all that camo and a muddy color, they can be tricky to spot – sometimes the submerged head looks more like a piece of driftwood than one of the planet’s most dangerous creatures! That’s woe to anyone who treads in their way. Big jaws with one of the strongest bites known to man are what await, along with the infamous croc death roll that’s specifically designed to rip flesh from bone. In the land of Pura Vida, these guys have been known to attack adult sea turtles. They can also do a whole load of damage to a human, although fatal attacks remain rather rare. American crocodiles are particularly active in the first few hours after sunset.


Image by Chris Martin from Pixabay

Costa Rica is one of the few places on the planet where the elusive and elegant jaguar can still be found in the wild. They are considered extremely vulnerable and have seen their populations decimated over the last few decades because of habitat fragmentation. However, they’re well protected in the surf-washed heart of Central America, where they thrive in the lush rainforests of the Corcovado National Park and the lush Golfo Dulce Forest Reserve. There are even rare examples of the black panther in the country, up with the higher woodlands of the Alberto Manuel Brenes Biological Reserve. Jaguars don’t present a major threat to humans, mainly because there are now so few around. However, they are still the largest cat species in the New World and are very adept hunters and stalkers.

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Neotropical rattlesnake

Neotropical rattlesnake
Photo credit: Yinan Chen @ Wikimedia

Central America might not have the same abundance of rattlers as North America, but the neotropical rattlesnake is surely up there with the most dangerous animals in Costa Rica. It’s big and thick set, with a wide body that’s painted dark brown with a dash of yellow down its side. Usually on the hunt for rodents in the country’s more arid and dry regions, the snake can cause some serious health problems in humans. It’s armed with neurotoxins that can cause shock blindness and shutdown of the respiratory system. Keep your distance and turn away if you hear that warning rattle!

Bull shark

bull shark
Photo credit: Albert Kok~enwiki @ Wikimedia

The bull shark isn’t to be taken lightly. With its beefy neckline and stout snout, these guys look like the bouncers of the ocean. That’s pretty much what they are too. They have an infamously aggressive nature and are very versatile in terms of habitat, being able to thrive in both salt- and freshwater areas. In Costa Rica, they’re known to accumulate around the Bat Islands, which sit just off the coast of the wild Santa Rosa National Park, or in the uber-remote Cocos Island National Park, almost halfway to the Galapagos! Strangely, oodles of intrepid travelers flock to those places to dive with bull sharks. That’s despite an attack that can rip up human flesh in a jiffy.

What is the most dangerous animal in Costa Rica?

That’s pretty hard to say. The truth is that there are oodles of dangerous animals in Costa Rica. Some live in the jungle reserves, others patrol the seas and salt waters around the coast of the country. Deciding which ones present the most danger to you will depend on where you’re going to be traveling. Hikers might want to pay special attention to the Fer de Lance snakes – they have excellent camouflage and are responsible for nearly half the bites in the territory. Swimmers and surfers will want to consider the sharks and crocs that hang by the river mouths and beaches.

Are there venomous snakes in Costa Rica?

Yes. There are quite a few venomous snakes in Costa Rica. The worst of them include the Fer de Lance – a pit viper that’s very unpredictable and can attack super-fast – and the eyelash viper, which has some of the world’s most deadly venom. The main areas of the country where you should be wary of snakes are the coastal lowland forests, like the ones in the Corcovado National Park and along the Nicoya Peninsula.

Are there dangerous spiders in Costa Rica?

Costa Rica has a few dangerous spiders. The black widow is the obvious one. It’s common all over the Americas and has a bite that can prove very painful. Worse than those are the so-called Brazilian wandering spiders. They’re bigger – up to seven inches across – and have a strong venom that can lead to death and heart palpitations. Pay special attention to those when handling fresh fruit, because they love to hide away in Costa Rica’s tasty bananas!

The most dangerous animals in Costa Rica: A conclusion

Costa Rica jungle
Photo by Niharika Bandaru on Unsplash

There are plenty of dangerous animals in Costa Rica. From yellow-blush viper snakes to tooth-wielding sharks, creepy crawly spiders to don’t-touch-me poison dart frogs, the fauna in this biodiverse part of the world isn’t always the safest. Still, the risk from the local animal life is pretty small to travelers. Snake bites and spider bites are rare. Shark attacks are few and far between. They’re worth having on the radar and being wary of, but shouldn’t spoil your dream of rafting around Arenal Volcano and surfing the beaches of Santa Teresa!


James Ardimento has spent the last 12 years journeying around the globe ! With its precious experiences and tips he gained around Asia, South America, Europe and the US he is a precious asset for this blog and for its readers