The 9 Most Dangerous Animals in Mexico: Top Mexican Killers

Mexico! Land of the Tequila, Tacos, and more than its fair share of glorious beaches, vibrant cities, and ancient Mayan and Aztec ruins. It certainly has a lot to offer that makes it a top holiday destination, including diverse wildlife!

But what may not be top of your list to experience is the sheer amount of dangerous beasts that lurk within the nation. Still, it is worth educating yourself lest you stumble into a dangerous critter on land or sea, right?

In this article:

  • Mexico has dangerous beasts lurking in the land and sea!
  • There are around 600 species of snake in Mexico with venomous varieties including vipers, coral snakes, sea snakes and colubrids.
  • Spiders can also be harmful in Mexico along with scorpions and some species of Lizard!
  • The most dangerous of all the animals in Mexico is the Fer-de-lance snake, the venom of which could kill a man!

Get ready to peek from behind your hands as we unveil the most dangerous animals in Mexico!

Does Mexico have poisonous snakes?

There are many, many reptiles within Mexico—and within this many varieties of snake. At around 600 species we could name, the most important ones to signpost here are the venomous species. These are categorised as Vipers, Coral Snakes, Sea Snakes, and colubrids.

Vipers are known for their thick muscular bodies and wide head. Their fangs are especially nasty, hinged in the front and usually an inch or so long. Perfect for sinking their teeth into prey. Their venom usually serves to debilitate their victims, ensuring they cannot escape as they slowly devour them in one go.

viper snake
Image by Artur Pawlak from Pixabay

Coral Snakes are much smaller and slimmer than vipers, but known for their vibrant colours. There are many species of these, and the minor differences in markings will tell you if they are poisonous or not. But only to the very trained eye.

Sea snakes dwell in the warm seas of the Gulf of Mexico and the pacific ocean. Characteristically shy and living on the seabed, you could live your whole life in Mexico without ever seeing one. They tend to avoid the shore and aren’t likely to attack.

Colubrids are the least antagonistic of the snake family. With large scales along the body, fewer on the head, and short teeth, their threat level is very minimal. If they were to bite a human, they could not break the skin.

If that isn’t creepy enough for you, we have three of these species listed in the 9 most dangerous animals in Mexico! So without further ado, let’s delve in and find out just how deadly they can be.

9 Most Dangerous Animals in Mexico, Listed & Explained!

1) Rattlesnake

Photo by sergeyskleznev

Usually found to the west in Mexico, these desert dwelling reptiles have been known to grow to 150 centimetres, nearly 5 foot in length! As nocturnal hunters, they tend to avoid the heat during the day by hiding underground where it is cool.

It is at night when you really have to watch out for these guys. As a subspecies of pit-viper, the ‘pit’ between their eyes is heat sensitive. This combined with its ability to sense even the smallest vibrations means it will sense you long before you see it. This may work in your favour, however, as they like to hunt small mammals, not humans. But if startled, the rattlesnake will strike!

One positive of the rattlesnake though is in the name. Its rattle is likely to alert you of its presence before you make any false moves. It pays to listen out for this.

If bitten, the venom can have neurotoxic effects, leading to brain damage and effects on the peripheral nervous system. This is uncommon however, and most likely you will escape with some blistering around the bite, some pain and possibly a little hypertension. Still, best to avoid all of this!

2) Coral Snake

coral snake

As already mentioned, this one is dangerous as it can fool you with its similar markings to non-venomous snakes within the species. So it’s worth memorising the style of marking and avoiding at all costs if you aren’t a herpetologist (student of reptiles/amphibians).

Luckily it will be easy to spot, usually around 18-20 inches in length and with red, black and yellow stripes. Its venom is said to contain some of the most powerful neurotoxins of any snake. Symptoms of a bite are known to be respiratory failure and paralysis. Luckily for us, the coral snakes (or coralillos in Spanish) fangs are rather weak. It generally delivers its venom via a chewing motion, rather than a single bite.

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There have been no recorded deaths of humans via a coral snake bite. But it is worth being mindful of their presence and the effects of a bite. Symptoms often are slow to show in humans, and if untreated with anti-venom can cause death.

3) Black Widow

black widow spider

Photo by Pelooyen

Most commonly found in Australia, it’s a little known fact that they are also found in Mexico! Vuida Negra in Spanish, whilst the black widow is not deadly, its bite and the venom delivered are very painful for the victim.

The venom can cause all sorts of physiological reactions such as chills or fever, nausea and vomiting, headaches, hallucinations, as well as increasingly intense muscle cramps and/or spasms for 12 hours after being bit. Chest and stomach pain, as well as hypertension and shock may also be experienced.

Anti-venom is always administered to reduce these symptoms, so it is best to seek medical help straight away!

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4) Chilean Recluse Spider

Photo courtesy of Faculty of Science, University of Helsinki

Both this and the black widow are the only 2 species of arachnid in Mexico that have fangs strong enough to pierce human skin. And this guy has some pretty harmful venom lurking within them! Said to be one of the most dangerous spiders in the world, one bite can cause various organs to fail if no antidote is provided. Even in some cases cause death! Certainly children, the elderly and those with weak immune systems are at risk.

The venom actually attacks the cells within the body, meaning that reactions can range from skin irritation, to the destruction of large areas of skin cells, to more complex cell destruction within the body. Terrifying indeed!

5) The ‘Gila Monster’ Lizard

Photo by Tommaso Urli on Unsplash

Latin name Heloderma suspectum, this and its sister species, the Mexican beaded lizard or Heloderma horridum are meant to be the only two species of lizard to contain venom. And there are over 5000 species across the globe!

Sadly for the Gila Monster, it has fangs similar to the Coral snake, meaning it cannot administer its venom through one bite. Rather through a chewing action. This bodes well for us humans. It is also slow moving by nature, so only really a danger to its prey. Still, it has a pretty fearsome reputation within its homes of Mexico and the southern states of America.

Legend amongst early Pioneers in the states had it that the lizard’s breath was so pungent as to be fatal. This is untrue, however, and though there have been some reports of adults bitten by the snake, these have not proved fatal. Reactions to a Gila monster bite include intense pain, fluid retention in the bit location, and rapid drop in blood pressure, followed by weakness.

6) Scorpion

Photo by Sippakorn Yamkasikorn on Unsplash

There are a few species that can cause harm to humans, but only 12 amidst the 200 or so species across the globe.

The species of scorpion that are found in Mexico are not as dangerous as Brazillian Yellow Scorpion, said to be the most deadly in South America. Death from a scorpion sting is still possible, however, and more likely to occur in children than adults. Yet it is the sheer amount of scorpions that exist within Mexico that make them so terrifying. They can lurk anywhere. So always check your shoes!

The effects of a scorpion sting in adults is said to range from numbness and swelling In the interim, before experiencing difficult breathing, bodily spasms, including in the neck and face, nausea and hypertension.

Alacramyn is an antidote developed by Mexican scientists that is readily available. Home remedies are also said to work well in adults, and include garlic, mango leaf, frankincense oil, basil and cortisone cream. Perhaps it is best to go down the medically approved route though!

7) Fer-de-lance Snake

Photo by Jan Kubita on Unsplash

This little number is a member pit viper species whose venom is the stuff of horror movies. Also known as barber amarilla (yellow chin or yellow beard) in Spanish, it is said to cause more deaths than any other reptile in South and Central America.

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On average, this snake delivers around 105mg of venom in a single bite. A dose of 50mg would prove fatal to an adult human. Symptoms of a bite range from all the general signs we have covered here—nausea, vomiting, low blood pressure, swelling or fluid retention, numbness and fever—to more disturbing such as bleeding from the nose, gums and gastrointestinal tract, and loss of consciousness. If untreated, the bodily organs can start to shut down.

If not treated quickly, the venom can destroy tissue and cells as it moves through the body, meaning amputation may often be needed. The venomous bite can be treated with anti-venom however, but must be done quickly to avoid long-term issues.

What is worse, this desert dwelling reptile is very aggressive and quick to strike. Chilling indeed! This beast can be found throughout the Gulf of Mexico, from southern Tamaulipas to Yucatán and Chiapas. So, if you plan on visitng, tread carefully.

8) Yellow bellied sea snake 

yellow bellied sea snake

Photo courtesy of What Lurks Below

So called because of its yellow belly, this sea-snake is mostly black on top. This makes it hard to see! But not to worry, whilst they sit on the sea-bed they’re generally docile and avoid attack. Cause for concern is only necessary if they are washed up on shore when injured, or if they are caught in fishermen’s nets. So the likelihood of coming across one is slim!

This is another reptile with hard-hitting venom, containing neurotoxins that can cause major damage to the brain if left untreated. Should you be one of the rare victims of a sea-snake attack, there are antidotes available that are said to act against the venom to neutralise its effects.

9) Box Jellyfish

Common to the Gulf of Mexico, these can often be seen swimming around near Cancun and the Riviera Maya, but only seasonally. Whilst perhaps not one of the most dangerous Animals in Mexico, it certainly has claim to be a nasty one.

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The jellyfish have an incredibly harsh sting if you cross them! This isn’t generally enough to kill a adult per se, but there was a case where a 4 year old boy died 40 minutes after receiving a sting from a box jellyfish. This is an extremely rare case, but the results of a sting can be quite harsh.

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Bodily reactions are reported as severe pain around the area, along with physiological reactions such as respiratory depression and cardiac dysfunction. Some victims have had to be resuscitated at the scene! Administered anti-venom is known to reduce pain and inflammation along with physiological symptoms, but the resultant rash lasts for months. It would be a good story presumably.

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Luckily, these sea-dwelling jellies only arrive between March and June, and are not overly common even during these times. Swimmers, divers and snorkelers would do well to wear a wetsuit during these times. Often resorts and the surrounding beaches will have jellyfish warning-signs posted on the shore.

So! What is the most dangerous animal in Mexico?

Without a shadow of a doubt, the most dangerous animal in Mexico has to be the Fer-de-lance Snake.

With a venom that could kill a man if left untreated, and even worse could cause severe life-long issues and even amputation if not seen to quickly enough. Snakes can be awesome, but this one is most certainly not!

You have braved the most dangerous animals in Mexico. Do you dare go track them down?

As mad as it might seem, there are a tonne of folks who go out into the deserts and jungles specifically to find these deadly beasts! If you have enjoyed hearing about them, perhaps you would like to pop on to YouTube and have a look at these intrepid explorers? We would prefer to pretend that they don’t exist.

That being said, Mexico is always worth a visit, and for-warned is most definitely for-armed if you are planning on going off the beaten track. Maybe stock up on anti-venom before you go as well. You know, just to be on the safe side.

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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