Golden Poison Dart Frog

“Aw, it’s so cute! Let’s just give it a cuddle!” NO. This adorably teeny frog is hiding enough poison in its skin to kill 20,000 mice, or more importantly, 10 people. All it takes is touching the skin to transmit the alkaloid poisons, which can quickly stop the heart of animals even larger than humans. Despite this incredible evolutionary advantage, the golden poison dart frog is somehow endangered, so chances are you won’t run into one on your way to work tomorrow. Unless you’re on the Pacific coast of Colombia, in which case, keep your eyes peeled.

Cape Buffalo

This is not your friendly neighborhood buffalo that would help you ford the river on the Oregon Trail. The Cape Buffalo is a familiar sight in African parks and reserves, part of the Big Five on the esteemed list of Most Dangerous African Animals. It is extremely unpredictable and antagonistic, often facing its predators head on and looking for opportunities to strike back. Hunters who have tried to take down Cape Buffalo often find themselves running for their lives as wounded would-be prey circle around behind their attackers to ram them with sharp horns in retaliation (they’ve even been known to kill large predators, such as lions). Not convinced? The Cape Buffalo is sometimes referred to as “Black Death.” How about now?

Brazilian Wandering Spider

Forget what you’ve heard about black widows and brown recluses – it is the Brazilian wandering spider that has the most potent neurotoxin of all. Although it is smaller than other spider species, and doesn’t always inject a full dose of its toxin with each bite, it is far more aggressive and territorial than the others. It likes to hide in dark, moist places near human settlements and wander out at night to seek prey. The good news is that the Brazilian wandering spider is also called “natural Viagra,” but don’t get too excited. The venom can cause erections in male victims, which can last for hours and lead to impotence. So be VERY careful what you wish for.

Box Jellyfish

People may doubt the existence of the Lochness Monster, but this sea creature is more terrifying and dangerous. Almost indistinguishable from other types of jellyfish except for its cube-like shape, the box jelly can have up to 60 tentacles, which can grow up to 15 feet each. Covered in stinging cells, each stinger is filled with a dangerous toxin that shuts down the nervous system of its prey. A single box jelly can have enough poison to kill up to 50 people. Found in the tropical Indo-Pacific waters and off the coast of Australia, it’s possible to survive an encounter with one of these killers, but many people drown due to paralysis before they make it back to shore. Fun fact: one of the box jellyfish’s only natural predators is the sea turtle, which has somehow developed immunity to the toxins.

Mosquito

At first glance, the mosquito seems significantly less terrifying than the others on this list. Usually, a mosquito bite leads to some scratching and mild discomfort, which can usually be mitigated by some good old calamine lotion. However, that one bite can also spread some of the most deadly diseases in the world, especially malaria, yellow fever, and West Nile virus. Not only that, they are found in abundance all over the world, especially in tropical areas, and it is difficult to avoid bites unless you are permanently wrapped up in a mosquito net. Due to the millions of people who die from mosquito-bourne illnesses each year, they can easily be considered the most dangerous animal in the world.

Saltwater Crocodile

This one at least seems pretty straight-forward: an animal with enormous teeth that can snap its jaw at over 3,000 pounds of pressure per square inch = dangerous killer. The saltwater crocodile can be found all over the world in slow-moving rivers and lakes, and does not discriminate in its prey. It is an ambush predator, skulking in the water and enabled by eyes and nostrils high on its head, before it lunges at its prey and drags it into the water to either swallow whole or drown by the formidable death roll. Killing over 800 people each year (in addition to sharks, water buffalo, hippos, and really anything that crosses its path,) this is one animal that Disney movies villainized for a reason.

Hippopotamus

Although they aren’t considered one of the Big Five, hippos are responsible for more deaths each year than any other animal in Africa. They are extremely territorial and aggressive defending their young, can weigh up to 8,000 pounds and run at speeds up to 20 mph. Although mostly herbivorous, their mouths can open up to four feet wide and crush down like a sledgehammer, which they don’t hesitate to do if threatened. Even if they don’t feel threatened hippos are known to attack without any provocation. However, you may want to be even more wary of the infamous hippo spray. After a hippo defecates, it flips its tail around in a circle at high speed to spray everywhere. Even more reason to keep your distance.

Komodo Dragon

Anything that has “dragon” in its name is automatically fear-inducing, and for good reason. Found in the Indonesian islands, the komodo dragon can grow up to 10 feet long and is notoriously an easy-to-please eater. It will eat anything it encounters, including birds, water buffalo, or humans. It will even dig up bodies from shallow graves if it has the opportunity. Although they only need to eat once a month, they hunt in groups, rip out their prey’s throat and wait as it bleeds out. They can weigh up to 200 pounds, and their saliva is frequently blood-tinged as mouth tissue is naturally lacerated during feeding. Just take a moment and picture a group of 200-pound lizard-dinosaur-monster hybrids dripping blood from their mouths coming at you, and go hide under the covers.

Carpet Viper

Most snakes are relatively harmless, but the carpet viper is not one of them. Responsible for most of snakebite deaths worldwide, their poison prevents victims’ blood from clotting so they normally bleed out. Additionally, as the carpet viper is often found in more remote areas of Africa and the Middle East, the lack of modern medical facilities makes it difficult for victims to receive the urgent care and anti venom they so desperately need after a bite. When they are about to attack, they form C-shaped coils and produce sizzling sounds such as water on a hot frying pan. So if you’re taking a walk in the deserts of Pakistan and think you hear somebody cooking eggs, watch your step.

Black Mamba

No, I’m not talking about Kobe’s killer three-pointer (#mambaarmystandup), although that is something to watch out for. The Black Mamba snake is sometimes referred to as “death incarnate,” and is found throughout Eastern and Southern Africa. It is extremely aggressive and fast, and its poison is almost always fatal unless the victim is able to get anti-venom very quickly. Although it normally will try to flee from humans, it will also attack without provocation. Myths and legends abound about the black mamba. As its habitat shrinks due to human encroachment, the number of encounters and attacks on people has become more prevalent. But don’t worry, it only takes a group of four or five people to kill one as it strikes in all directions with over a third of its significant body above ground.