10 Deadliest Animals on Earth, Ranked by Human Deaths

Ask a room full of people to name the deadliest animals on Earth and you’ll hear the usual suspects: great white sharks, lions, maybe a grizzly bear. Those animals make terrifying movie villains. They barely register in the real body count, which is dominated by creatures you could flatten with a rolled-up newspaper.

This list ranks animals by estimated human deaths per year, using World Health Organization figures and other widely cited sources. Treat every number as an estimate. Many deaths happen in rural areas where nobody files a report, and figures can vary wildly between sources. We’ve also left one species off the list on purpose. You’ll find it waiting at the end.

10Tsetse Fly

In 1998, health workers across Africa reported almost 40,000 cases of sleeping sickness, and the WHO estimated that roughly 300,000 more went undetected. The culprit was a bloodsucking fly about the size of a housefly, carrying a parasite called Trypanosoma brucei. Once the parasite reaches the brain, it scrambles the sleep cycle and causes confusion and personality changes. Left untreated, the disease is usually fatal.

Tsetse flies are strange insects in their own right. Both males and females drink blood, and instead of laying a clutch of eggs, a female grows a single larva inside her body at a time, feeding it a milky secretion. The flies infest nearly 10 million square kilometers of sub-Saharan Africa, where they also spread nagana, a related disease estimated to kill around 3 million cattle a year.

So why does a fly with that résumé sit at No. 10? Because people fought back. Active screening, better drugs and cheap fly traps drove reported human cases down to 837 in 2022, the fifth straight year below 1,000. A widely shared 2014 chart from the Gates Foundation credited the tsetse with about 10,000 deaths a year. Today’s toll is almost certainly a small fraction of that, making this the rare entry whose ranking is sinking fast.

9Hippopotamus

A hippo spends most of the day half-submerged, blinking slowly like a bored commuter. That sleepy act fools a lot of people. Hippos are widely estimated to kill around 500 people a year in Africa, a figure repeated by the BBC and National Geographic, although no agency keeps a continent-wide tally.

Most fatal encounters happen in or near water. Hippos guard their stretch of river or lake with real fury, and fishermen in dugout canoes are frequent victims when a bull decides a boat has come too close. On land, the danger peaks after dark, when hippos leave the water to graze. Anyone standing between a hippo and its river becomes an obstacle. The animal’s jaws can open to about 150 degrees, and its lower canines can reportedly grow to about 50 centimeters (20 inches).

Here’s the odd part: for all their time in the water, adult hippos can’t really swim. They’re too dense to float, so they walk or gallop along the bottom and push off the riverbed in slow, bouncing leaps. On land, they move far faster than their barrel-shaped bodies suggest and can outrun a person over a short distance.

8Elephant

In India alone, elephants killed 628 people in 2023, according to government figures, and 2,853 over the five years from 2019 to 2023. That one country’s total already outpaces the commonly quoted toll for hippos across all of Africa, before you add deaths in Sri Lanka, Kenya, Tanzania and elsewhere.

Very few of these deaths involve a rogue elephant on a rampage. They’re collisions of geography: farms carved into old migration routes, villages pressed against shrinking forests, and hungry herds raiding crops at night. People die trying to chase elephants off their fields, or walking home in the dark and stumbling into an animal they never saw. A big Asian elephant can weigh around 4 tons and an African bush elephant more than 6, so a single shove can be fatal.

Bull elephants in musth, a periodic state of surging testosterone, are especially unpredictable. The conflict cuts both ways, though. India’s government reported 528 elephants killed by unnatural causes such as electrocution, train strikes and poaching over a recent five-year span. Conservationists now focus on early-warning systems, wildlife corridors and fencing that keeps both species alive.

7Crocodile

A crocodile can lie motionless at the water’s edge for hours, with only its eyes and nostrils breaking the surface, then cover the final few feet in a blur. Crocodiles are commonly estimated to kill around 1,000 people a year, though the true figure is hard to pin down because many attacks happen in remote villages and never make the news.

The Nile crocodile is the worst offender by a wide margin. One study estimated it attacks somewhere between 275 and 745 people a year, with about 63 percent of those attacks proving fatal. It shares rivers with people who fish, bathe, wash clothes and collect water, often because there’s no other water source nearby. The saltwater crocodile, which ranges from India to northern Australia, is even bigger: large males can exceed 6 meters.

Crocodiles rarely chase. They ambush, clamp down and drag prey underwater, sometimes spinning in a “death roll” to tear off pieces. In a 2012 study of crocodilian bite forces, a saltwater crocodile registered about 16,400 newtons, one of the most powerful bites ever measured in a living animal. Oddly, the muscles that open the jaws are weak, which is why a few wraps of tape can hold a croc’s mouth shut.

6Scorpion

Of the roughly 2,500 known species of scorpion, only a few dozen carry venom strong enough to kill a person. Those few do a startling amount of damage. Researchers estimate there are more than a million scorpion stings worldwide each year and around 3,000 deaths.

Children are at greatest risk, because a dose of venom that makes an adult miserable can overwhelm a small body. The hotspots are places where dangerous species share homes with people: Mexico, northern South America and southeastern Brazil, North Africa, the Middle East and the Indian subcontinent. Scorpions hide in shoes, bedding and wall cracks, and most stings happen at night or when someone reaches somewhere they can’t see.

The worst offenders belong to a single family, the buthids. The list includes the deathstalker (Leiurus quinquestriatus) of North Africa and the Middle East, the fat-tailed scorpions of the genus Androctonus, Mexico’s bark scorpions, and the Brazilian yellow scorpion, Tityus serrulatus, which can reproduce without males and has spread through Brazilian cities. Their neurotoxins disrupt the way nerves fire, which can lead to heart and breathing failure in severe cases.

5Kissing Bug (Assassin Bug)

The kissing bug earned its sweet nickname in the least romantic way possible. It creeps out at night and feeds on sleeping people, often around the mouth and face. Most victims never feel a thing.

The bite itself isn’t the real problem. Kissing bugs, a group of assassin bugs known as triatomines, often defecate while they feed, and their droppings can carry Trypanosoma cruzi, the parasite behind Chagas disease. When a drowsy victim scratches the bite or rubs an eye, the parasite slips in. The WHO estimates that about 8 million people are infected, mostly in Latin America, and that the disease causes more than 10,000 deaths a year.

Chagas is a slow, sneaky illness. After a mild early phase that’s easy to mistake for flu, the parasite can hide in the body for decades before damaging the heart or digestive system in a significant share of chronic cases. Many people never know they’re infected. The disease is named for Brazilian physician Carlos Chagas, who in 1909 linked the parasite, the bug and the illness in patients in the village of Lassance, Minas Gerais. More than 100 million people are considered at risk.

4Freshwater Snail

The fourth-deadliest animal on Earth is about the size of a fingernail and has never chased anyone in its life. Certain freshwater snails, especially in the genera Biomphalaria and Bulinus, serve as hosts for parasitic flatworms called schistosomes, or blood flukes.

The snails release swarms of microscopic larvae into the water. Anyone who wades, swims, fishes, farms or washes clothes there can be infected as the larvae burrow straight through the skin. The adult worms settle in blood vessels and can live for years, shedding eggs that lodge in the bladder, intestines and liver. The WHO says at least 253.7 million people needed preventive treatment for schistosomiasis in 2024. Its estimate of about 14,000 deaths a year is, by its own account, likely an undercount, and some older estimates ran far higher.

This is an ancient disease. In 1910, pathologist Marc Armand Ruffer found calcified schistosome eggs in Egyptian mummies around 3,000 years old. Modern engineering can make it worse: large dams and irrigation canals create the calm, warm water that snails love, and outbreaks have followed several major water projects in Africa.

3Dog (Rabies)

The animal curled up at the foot of millions of beds is, by a wide margin, the deadliest mammal on this list. Bites themselves rarely kill. Rabies does, and according to the WHO, dogs are responsible for up to 99 percent of human rabies infections.

The WHO’s most recent modeled estimate puts rabies deaths at roughly 44,000 a year, while an older, widely cited estimate was 59,000. Both are likely undercounts, since many victims die at home without a diagnosis. Most deaths occur in Asia and Africa, and about 40 percent of victims are children under 15, who are more likely to be bitten and less likely to report it. Once symptoms appear, rabies is virtually 100 percent fatal.

The tragedy is that every one of these deaths is preventable. A prompt course of post-exposure vaccine after a bite works extremely well, and vaccinating dogs stops the virus at its source. Latin America has used mass dog-vaccination campaigns to slash dog-transmitted rabies in humans by well over 90 percent since the 1980s. The hard part isn’t science. It’s getting vaccines into rural clinics and getting people there in time.

2Snake

Every year an estimated 5.4 million people are bitten by snakes, and somewhere between 81,000 and 138,000 of them die, according to the WHO. Around three times as many survive with amputations or other permanent disabilities.

The burden falls hardest on rural South Asia and sub-Saharan Africa, on farmers, laborers and children who walk barefoot through fields or sleep on the floor. India is the epicenter: a large 2020 study estimated that about 1.2 million Indians died from snakebite between 2000 and 2019, an average of roughly 58,000 a year. Russell’s viper caused the largest share, alongside the saw-scaled viper, the Indian cobra and the common krait, known together as the “Big Four.”

In 2017, the WHO added snakebite envenoming to its list of neglected tropical diseases, which helped bring attention and funding to a problem long ignored. The core treatment, antivenom, saves lives but is often expensive, in short supply or hours away from the people who need it. Researchers are now testing new approaches, including lab-designed antibodies and pills that could be taken on the way to a hospital.

1Mosquito

No animal has shaped human history like the mosquito, and by most estimates no animal kills more of us today. Malaria alone killed about 610,000 people in 2024, according to the WHO, out of roughly 282 million cases. About 95 percent of those deaths were in Africa, and most of the victims there were children under five.

Malaria is only the headline. Mosquitoes also spread dengue, yellow fever, Zika, chikungunya, West Nile virus, Japanese encephalitis and lymphatic filariasis. Dengue set records in 2024, with more than 14 million reported cases and roughly 9,000 reported deaths. Add it all up and estimates of mosquito-related deaths commonly land somewhere between 700,000 and a million a year.

Only female mosquitoes bite, because they need protein from blood to develop their eggs. They find us by tracking exhaled carbon dioxide, body heat and skin odors. The fight back is getting more creative. Two malaria vaccines, RTS,S and R21, are now being rolled out across Africa. And in a trial in Yogyakarta, Indonesia, releasing mosquitoes infected with Wolbachia bacteria, which block dengue transmission, cut dengue cases by about 77 percent.

So… Who Should You Actually Fear?

The pattern is hard to miss. The animals that kill the most people aren’t the biggest or the fiercest. They’re the ones that carry parasites and viruses, thrive near poverty, and strike where clinics are far away. Most of these deaths are preventable with bed nets, vaccines, clean water and antivenom.

And the species we left off the list? Humans. United Nations figures put intentional homicides at roughly 450,000 a year, which would rank us second, right behind the mosquito. For gentler company, meet the animals with real-life superpowers or the deep-sea creatures that look like aliens.

Quick answers

What is the deadliest animal in the world?

The mosquito is the deadliest animal in the world by a huge margin. Malaria alone killed about 610,000 people in 2024, according to the WHO, and mosquitoes also spread dengue, yellow fever, Zika and other diseases. Combined estimates of mosquito-related deaths commonly range from about 700,000 to a million people a year.

How many people do sharks kill each year?

Very few. According to the International Shark Attack File, unprovoked shark bites caused an average of about eight deaths a year worldwide from 2020 to 2024. In 2025 it confirmed 65 unprovoked bites and nine unprovoked fatalities. You’re far more likely to be killed by a dog, a snake or a mosquito-borne disease.

What is the deadliest mammal to humans?

Dogs are the deadliest mammal to humans, almost entirely because they transmit rabies, which kills an estimated 44,000 to 59,000 people a year. Among wild mammals, elephants and hippos top the list. Elephants killed 628 people in India alone in 2023, and hippos are estimated to kill around 500 people a year in Africa.