It is actually hard to determine what the most aggressive animals are because any creature can be violent if provoked. Yet some animals are more prone to aggression than others.
The truly surprising thing is the number of seemingly harmless species that appears on the list of the world's most vicious animals. Many creatures that are normally thought of as docile, friendly, or even cute can be quite aggressive. Yet some beasts often characterized as dangerous are actually rather harmless.
8 Most Aggressive Animals in the World
The Grizzly Bear
The most aggressive species of bear in North America is also the largest one – grizzly bear. Since grizzlies are too large to climb trees for safety, their preferred mode of defense is to attack. Female grizzlies with cubs will almost always attack people that come near them. Despite what some people think, bears do not attack humans; instead, they defend themselves. Grizzlies are particularly frightening creatures: some of them can weigh up to 1,2000 pounds and stand up to nine feet in height on their hind legs.
The African Honey Bee or "Killer Bee"
Africanized honey bees, or killer bees, have become one of the most feared creatures on earth because they attack in a swarm. During the attack, thousands of bees sting a victim to death. The killer bee's sting is no more dangerous than a regular sting, but the combined venom of thousands of stings can lead to a painful death. Africanized bees are particularly frightening because they look like regular honey bees. They also have the nasty habit of invading and taking over the hives of regular honeybees, which they wipe out. In South Africa, they have all but wiped out regular bees.
The Saltwater Crocodile
The largest living reptile in the world is also one of the most aggressive animals in the water. These crocodiles can grow up to 17 feet length. Even though it is a lethargic creature, this crocodile can move through the water at two to three times the speed of a human swimmer. They can attack quickly and suddenly, which makes them dangerous. Interestingly enough, saltwater crocodiles can swim across long distances of the sea. They have been observed eating water buffalo and even sharks. The salt water crocodile has the strongest bite of any animal in the world, meaning few people can survive from their attacks.
The Western Diamondback Rattlesnake or Crotalus Atrox
Crotalus atrox, this familiar sight in the Southwestern USA and Northern Mexico is one of the most aggressive creatures in the world. When threatened, they curl up, make the distinctive rattling sound, and strike suddenly. Unusually, they stand their ground and fight rather than run away when confronted with a foe. They attack with deadly venom that can destroy tissue and cause heart failure if left untreated. These snakes are often seen crossing roads and even crawling on porches in Arizona and New Mexico.
The Great White Shark
This sea-going predator can grow up to 20 feet in length and weigh several thousand pounds. They only become aggressive when feeding. One particularly frightening practice of the great white is to rear its head above the surface of the water in order to attack and bite. The Great White is particularly feared because it attacks seals and other animals from below. They can also strike at incredible speed and have the ability to jump out of the water. Great Whites are unique because their main prey is marine mammals such as seals, although they sometimes mistake human swimmers for that prey.
The Rhinoceros
Known for their large size, horn, and armored skin, rhinos are the second largest land animal in the world. They are also an extremely aggressive creature that will charge almost anything, including people in cars. The danger from them is great because rhinos have notoriously bad eyesight. Despite their aggression, wild rhinos are now in danger of extinction because of an even more aggressive species: man. Rhino horns are extremely valuable on the black market, so they are often killed for their horns with high-powered rifles. Some experts now think there might not be enough rhinos in the wild for the species to survive.
The Hippopotamus
It is hard to believe, but hippos are one of the most aggressive animals in the world. When they are not attacking other species, male hippos fight each other. Hippos are also one of the few animals that will attack people with no provocation. Each year dozens of people are killed in Africa when hippos sink their boats. Hippos are particularly frightening because they are the third largest land animal in the world. Incredibly, they are also herbivores that mainly eat grass.
The Tasmanian Devil
The world's largest carnivorous marsupial is also one of the world's most effective predators. They've been known to attack and eat entire sheep on the Australian island of Tasmania. The devil is so aggressive because of its high metabolic weight: to survive, one has to eat 16 to 17 pounds (around seven kilograms) of meat a day. They will attack and eat almost any potential source of meat, including leather shoes. When they eat, the devils will consume an entire animal, even its bones and fur, if they get the chance.