Facts about the animal kingdom

The Most Aggressive Animals in the World

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. Updated: August 30, 2017
The Most Aggressive Animals in the World

Contrary to what many believe, there are many very shy and peaceful animals that are extraordinarily lethal. A sample is the sea serpent, who will flee before creatures that do not enter into their food alternative. Another example is the stoat, a diminutive being of only 300g, capable of successfully dealing with prey much larger than them thanks to their unparalleled ferocity. However, a stoat does not cause human victims, something the sea serpent does (although very few).

Our concept of aggression has more to do with the absence of fear of superior beings in size and strength, facing them without hesitation. We also value the ability to predation, there are carnivorous animals that must consume their weight every day to survive. Obviously this forces them to be authentic killing machines.

Finally, we value territorial aggressiveness. There are species that will defend their territory with their teeth or horns. To explain more, here is our list of the most aggressive animals in the world.

You may also be interested in: The 10 Most Solitary Animals in the World
  1. Mustelids
  2. Wolverine
  3. Honey badger
  4. Shrews
  5. Hippos
  6. The Mantis
  7. Leopard seal
  8. Mongoose
  9. The most dangerous animal


The mustelids are a family of animals among which are some of the most ferocious and aggressive on the planet. Fortunately for man and the rest of the animal kingdom, the wisdom of nature has constrained this enormous capacity to kill in small bodies.

The stoat, Mustela ermine, has more than 30 subspecies distributed throughout the planet. It is the smallest of the mustelids (100 to 300 gr.), but this does not prevent them from hunting prey 20 times heavier. The hunting technique employed is to surprise their prey from behind and bite them on the nape with their razor-sharp teeth. They will not stop attacking until their victim is bleeding and dies. They have a brilliant agility of movement. If you have ever thought that keeping a stoat as a pet would be a good idea, you probably did not know this information!

The Most Aggressive Animals in the World - Mustelids


The wolverine, Gulo gulo, after the giant sea otter is the second largest of the mustelids. Their solid, compact and muscular aspect resembles more that of a small bear than that offered by most mustelids who are slender and stylized. Their ferocity, strength and predatory ability are legendary. It is known that they are not afraid to face wolves or bears, which forces them to retreat. These great predators know that it is not a wise idea to fight with a wolverine.

One fact about the wolverine's fur is that it never freezes, which is why it is used to border hoods of clothes worn on arctic and antarctic missions. Humans in these extreme climates need to protect their faces efficientlyWolverines inhabit the northern boreal forests.

The Most Aggressive Animals in the World - Wolverine

Honey badger

The honey badger, Mellivora capensis, is a mustelid which measures 85 cm by 30 cm and weighs 14 kg. They are known for its unparalleled ferocity as they confront their predators (leopards and lions) without retreating and on many occasions they even make them give up their hunting spirit. The honey badger's specialty when fighting against lions or leopards is to look for their crotch and cause wounds with their powerful nails and teeth in the "family jewels". Therefore, many of them sensibly give up hunting.

There are many more examples of ferocity among mustelids, but the three above are good examples of their congenital aggressiveness.

If it is not for sudden weather changes, mustelids in general are not threatened. On the contrary, they are spreading and killing other native species.

The Most Aggressive Animals in the World - Honey badger


The family soricidae includes small beings called shrews. The smallest of them measures a maximum of 5 cm, with a maximum weight of 3 grams. The largest shrew is up to 15 cm, and weighs close to 100 g.

These animals are killing machines. They cannot live more than 4 hours without eating, since they need to consume all their weight in insects, worms, lizards, mice or snails every day.

  • The shrew, Suncus etruscus, is the smallest of its kind. It does not exceed 5 cm, nor does it exceed 3 g of weight. The heart rate of this animal is a brutal figure: 1200 beats per minute. It is the smallest terrestrial mammal, but due to its high energy expenditure cannot stop eating insects.
  • The home - grown shrew, Suncus murinus, is the largest of its kind. They need to eat incessantly because their metabolism is very high. They chase mice, although they do not exceed 100 g, and measure a maximum of 15 cm. But they also feed on lizards, carrion, worms and even rats! Shrews secrete a poison that weakens their prey.
The Most Aggressive Animals in the World - Shrews


The hippopotamus, Hippopotamus amphibius, despite being herbivorous animals are very dangerous because of their aggressiveness. They are the animals that cause more human victims in the African continent (apart from mosquitoes that inoculate diseases).

Males are larger than females. There are records of hippopotamuses measuring 5.2 meters and 4500 kg of weight. There are 4 subspecies distributed throughout sub-Saharan Africa. They can live 40 years, or 50 if they are captive in zoos. Despite their volume they can reach 30 km/h for short distances.

Hippos have historically been considered the most dangerous mammals for humans in Africa. One telling fact is that Pharaoh Narmer (the first Pharaoh, who united High and Lower Egypt), died as a result of a hippopotamus attack during a hunting party.

The Most Aggressive Animals in the World - Hippos

The Mantis

The mantodea is an order that includes mantises, whose better known representative is the praying mantis. All mantids devour other insects, and even larger ones can devour mice, frogs and other small vertebrates. They are very aggressive insects, but they are not dangerous. They have no poison. Occasionally they practice cannibalism.

The praying mantis is found almost everywhere. The aggressiveness of the mantis is harmless to humans, but lethal to the rest of insects.

The females are bigger than the males and some have a very ugly habit: they eat the males while they are copulating or after finishing! Even if the courtship of the male does not convince the female, she can have him as a snack.

Another horrifying custom is that when they catch a prey, they begin to eat it alive, while the victim is torn between their serrated legs. Watching a mantis hunt a prey, and seeing them immediately start engorging them as they are alive is a creepy sight.

The Most Aggressive Animals in the World - The Mantis

Leopard seal

The leopard seal, Hydrurga leptonix, is a tremendously aggressive animal. They do not fear anything or anyone. So much so, many biologists and naturalists who study Antarctic fauna leave research to their colleagues. So they can make discoveries about this enormous unknown fish instead of them.

Adult females are larger than males, reaching 4 meters and weighing 600 kg.

Their habitual prey are emperor penguins, other seals, fish, squid and carrion. Killer whales and large sharks hunt young leopard seals, but they do not usually attack adults.

Leopard seals have relatively small mouths for their size, so they use a brutal hunting technique. Once they have strongly bitten any part of their prey, they shake their head with extraordinary violence to hit the victim off the ground until they are finished. If they hunt in the water they tear off pieces of their prey.

Image of a National Geographic Leopard Seal:

The Most Aggressive Animals in the World - Leopard seal


Herpestidae is the family to which the mongoose belongs. Currently there are 33 species of mongoose, and a common feature is their aggressiveness. They are found in Eurasia and Africa. Their measurements and weight oscillate between the 30cm and 280g in mongoose dwarfs, to 120cm, and 4kg in the white-tailed mongoose.

The mongoose (Herpestes ichneumon) like other species of herpestids, can eat snakes, some of them poisonous. They measure up to 60cm, and their weight oscillates between 2 and 4kg. If they are cornered they will not hesitate to face against lions.

Mongooses are distributed throughout the temperate and equatorial zones of the planet. In rural India it is common to have a domestic mongoose, whose function is to hunt rodents, but also serpents of all kinds, including snakes.

The Most Aggressive Animals in the World - Mongoose

The most dangerous animal

Any female protecting her offspring, whatever the species, may become extremely aggressive. A mother will kill or sacrifice herself to protect her offspring. Motherly love is a force to be reckoned with!

The Most Aggressive Animals in the World - The most dangerous animal

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The Most Aggressive Animals in the World