They say that nice guys finish last, a sentiment with which this motely crew of mammals, reptiles, birds, fish, amphibians and insects would surely agree.
As some of the most aggressive species on the planet, they’ve figured out that offence is often the best defence, whether you’re a bull shark headbutting its prey, a honey badger taking on a lion or a horsefly repeatedly returning to draw blood from the same host.
As with most species out there, many of those on this list won’t attack unless provoked – so best to steer clear, and not tempt their wrath.
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World's most aggressive animals
1. Honey badger (Mellivora capensis)
Don’t be fooled by the cutesie name. This medium-sized mammal, a relative of skunks and otters, isn’t afraid to use its long claws and sharp teeth to defend itself and its burrow from anything it regards as a threat.
That even includes lions and hyaenas across the honey badger’s range in sub-Saharan Africa. Also found throughout Saudi Arabia, Iran and western Asia, the species is omnivorous, feeding on everything from insects and small birds to berries and bulbs.
Its common name (the proper name is ratel) comes from its love of honey and bee larvae, for which it will withstand countless stings as its rummages around honeybee nests.
When threatened, the honey badger will emit a foul-smelling liquid from a gland at the base of its tail, yet another reason to leave it alone.
2. Nile crocodile (Crocodylus niloticus)
Nile crocodiles are Africa’s largest crocodilian, growing up to around 6m long and weighing up to 900kg. As such, they are fearsome predators, ready to take down wildebeest and small hippos that cross their path – though their primary diet is fish.
With eyes (Nile crocodiles can see well by day and night), ears and nostrils on the top of its head, the species is well adapted for staying submerged in water, laying in wait for prey to ambush.
When the moment comes, it can move at lightning speed, grabbing its victim with powerful jaws and pulling it underwater to drown it.
Attacks by Nile crocodiles on humans are unfortunately fairly common, owing to the fact that there’s quite a lot of crossover in our habitats – and because of the crocodile’s strength and speed, these attacks are often fatal.
3. African buffalo (Syncerus caffer)
The African buffalo is not short of predators – this cow-like herbivore is on the menu for lions, hyenas, leopards and African wild dogs, as well as humans, for bushmeat.
But it’s far from an easy target. An aggressive streak that kicks in when an individual senses a threat to itself or another member of its herd.
Divided into four sub-species – the cape buffalo, forest buffalo, West African savanna buffalo and Central African savanna buffalo – these animals can be found in many different habitats across most of the African continent.
Herds can number in the thousands, and are liable to charge when threatened – an alarming prospect for the creature being charged, given that African buffalo can run at up to 37 miles per hour.
The shape and size of the buffalo’s horns vary depending on the sub-species, but are always formidable, capable of doing serious damage to anyone who attempts to take them on.
4. Gulls
It doesn’t matter how many times you’ve had a chip stolen out of your hand by a gull, it’s always a shocking experience. Albeit one that leaves you with a begrudging respect for the boldest of our avian friends.
Gulls (‘seagull’ is a misnomer as many of these varied family of seabirds are now found far from the sea) are intelligent creatures. They’ve adapted their behaviour to take advantage of the feeding opportunities that come from living among humans.
In the UK, herring gulls (Larus argentatus) and lesser black-backed gulls (Larus fuscus) are two of the species most likely to divebomb you for your snacks, but attacks can also be motivated by an adult fearing for its chicks.
5. Black rhino (Diceros bicornis)
Black rhino are mostly solitary creatures, with individuals of both sexes sticking to their own territory. They scent mark this territory with urine spraying, dung piles and head rubbing (they have a special gland for the purpose).
Their territorial nature also manifests in aggression against anything that is perceived as a threat, whether another rhino or a human that gets too close (it’s quite common for black rhino to charge tourist vehicles in national parks).
Found throughout southern and eastern Africa, black rhino can charge at up to 35 miles per hour, using their massive bulk (males weigh up to 1,350 kg) and tough horns (which are made of keratin, not bone) against any unwitting opponent.
Because the black rhino has poor vision – relying instead on excellent hearing and sense of smell – they will sometimes charge inanimate objects such as rocks or trees.
6. Bull shark (Carcharhinus leucas)
You would not want to meet a bull shark when out for a dip. Living in coastal waters all over the world, these predators – alongside great white sharks and tiger sharks – are the most likely shark species to attack humans.
With specially adapted kidneys that enable them to retain salt when in freshwater, you’ll find them in brackish water too, and even far inland, up rivers – they’ve been spotted 2,400 miles up the Amazon River.
The bull shark gets its name from its blunt snout and its hair trigger demeanour. Its attack pattern is also similar to its terrestrial namesake, involving a headbutt before chomping down with a mouth full of razor-sharp teeth.
7. Black mamba (Dendroaspis polylepis)
One of the world's deadliest snakes, the black mamba, which can be found in hill and savanna habitat across eastern and southern Africa, isn’t one to pick a fight with a human. If threatened, however, it will attack with deadly force.
First the snake rears its head and upper body up to 1m off the ground, displaying the black inside of its mouth – the reason for its name, as its skin is actually an olive-grey.
It will then strike multiple times, using a pair of fangs at the front of its upper jaw to administer a neurotoxin strong enough to kill a human within 20 minutes, depending on the number of bites.
Male black mambas wrestle each other over mating rights, writhing around with their 2m-long bodies entwined in order to ascertain dominance.
8. Horsefly (genus Tabanus)
If you’ve ever gone horse riding in really hot weather, you’ve probably experienced the tiny terror that is the horse fly. There are over 4,500 species of this blood-sucking insect, with every region represented except for the poles; in the UK we have 30 species.
Just like mosquitos, it is only the female that bites – she needs a meal of blood to help develop her eggs after fertilisation. Any large mammal will do, as her mouthparts – a pair of serrated mandibles – are able to cut through even very thick skin.
Horsefly bites are particularly painful because, unlike mosquitos, horseflies do not administer an anaesthetic. They also use small hooks on their jaws to help them stay in place while sucking blood. On top of all that, these insects are tenacious, returning to the same animal again and again until they’ve had their fill.
Covering up is the best way of avoiding being bitten, but even this method is not foolproof – those sharp mandibles can cut through clothing.
9. Triggerfish
These 40 species of the Balistidae family get their name from a trigger-like mechanism on their dorsal fin that makes them appear larger when threatened by a predator.
But that name also happens to be a pretty apt description for their general demeanour too, as these fish are some of the most aggressive you’ll come across.
Living mainly in water less than 50m deep, on coral reefs, all over the world, they are mostly solitary, with males establishing territories that they defend fiercely. Attempt to approach a triggerfish’s seafloor nest – where both parents keep tens of thousands of eggs oxygenated by blowing water over them – and you risk an aggressive charge.
Get bitten and you’ll know about it: their hard, crustacean-crunching teeth are capable of inflicting a painful wound.
10. South American horned frog (genus Ceratophrys)
It’s hard to find more voracious predators than the eight species of South American horned frog that inhabit grassland and rainforest habitat across that continent.
These quite large frogs – measuring as much as 17cm across – eat all manner of frogs, lizards, snakes, birds, crabs, insects and rodents, and won’t hesitate to snack on creatures almost as big as themselves.
They’re able to do so thanks to a disproportionately large head compared to body size, as well as an extremely wide mouth. It’s for these characteristics that South American horned frogs are also known as Pacman frogs, after the computer game character.
Amazingly, the bite force of a South American horned frog has been found to be comparable with that of medium to large mammals. This, along with its sharp, curved teeth and long fangs, plus a sticky tongue that can latch onto fur and feathers, makes it best avoided if you don’t want to end up as lunch.
The frog’s aggression sometimes gets the better of it. However, it’s been known for them to choke when attempting to eat too large a prey animal.
