1. Lion
   Tiger
2. Jaguar
   Cougar

The only time you want to see a lion is on safari or at the zoo. Walking into a lion's territory isn't a good idea. They're known as the king of the jungle (although they don't really live there) for a reason, and no animal on Earth would enter its territory and hunt it.

1. Panda bear
   Black bear
2. Polar bear
   Brown bear

Polar bears live in the Arctic so you will never stumble upon one by accident, but since hunting in the Arctic is a grueling lottery, these bears will eat whatever they can once given the chance. Getting caught in their territory is extremely dangerous.

1. Driver ants
   Bulldog ants
2. Cockroaches
   Fire ants

Driver ants roll about 20 million deep and destroy any animal in their path. Not even an elephant wants to deal with 20 million ants and will avoid the swarm when it's on the attack. The ants don't hunt elephants, however. They hunt other insects like grasshoppers and wasps, and they can attack half a million animals a day.

1. Red paper wasp
   Carpenter bee
2. Africanized honeybees
   Asian giant hornet

Africanized honeybees are known to attack under threat and when they attack, they attack repeatedly in huge numbers, sometimes proving fatal. "Killer" bees are on Earth because somebody crossbred two aggressive species and then accidentally let the swarm escape. They kill about two people per year.

1. Cape buffalo
   Asian buffalo
2. Jersey cattle
   Red Angus

The Cape buffalo or African buffalo is one of the "Big Five" game animals and is threatened by trophy hunters. It is known as the "black death" and is said to have killed more hunters than any other animal. It will circle and tire out its prey before going in for a kill, and it becomes more aggressive once wounded.

1. Black rhino
   Saltwater crocodile
2. African elephant
   Hippopotamus

The rhino is another prized trophy for hunters and is under threat of extinction because of poachers and hunters. If you get caught in the wrong place at the wrong time, you could find yourself trying to outrun this beast that can run 30 mph and is insanely agile. You can't dodge it like a matador dodges a bull.

1. Elephant
   Alligator
2. Rhino
   Hippopotamus

A hippo is an 8,000-pound animal that can charge at 30 mph and has two long, razor-sharp teeth that can chomp down with 2,000 pounds of force. Anyone who has learned anything about animals knows to stay away from this one.

1. Eagle
   Flamingo
2. Cassowary
   Ostrich

These birds won't attack humans for no reason, but if you cross their path it could be fatal. It would take a lot of strong blows for it to kill a human, and it would only do so in self-defense. They have killed humans before and they are mostly found in Australia.

1. Wolverine
   Skunk
2. Honey badger
   Stoat

You may know about the Marvel hero named Wolverine who is named after this animal with sharp claws and teeth. Wolverines are from the weasel family but look like they belong in the bear family. They're strong and powerful hunters that prey on everything from mice to caribou.

1. Tasmanian devil
   Least weasel
2. Honey badger
   Komodo dragon

The only place you can find a Tasmanian devil in the wild is on the Australian island state of Tasmania. It's a marsupial that can grow as large as a small dog and can hunt prey as large as a small kangaroo.

1. Taipan
   Anaconda
2. King cobra
   Black mamba

The black mamba is the longest venomous snake in Africa, and just two drops of the snake's venom can kill a human. Its venom will shut down the nervous system and paralyze a human in less than 30 minutes.

1. Meishan pig
   Black Slavonian hog
2. Domestic pig
   Wild boar

The scariest wild animals are the intelligent ones, and boars are some of the smartest animals on the planet. They display unpredictably erratic behavior when threatened, and you don't want to be circled by one of these 600-pound beasts equipped with razor-sharp tusks.

1. Dwarf crocodile
   American alligator
2. Chinese alligator
   Saltwater crocodile

A saltwater crocodile can reach 17 feet long and 2,200 pounds. If that's not scary, it can charge at close to 20 mph in water. The saltwater crocodile readily attacks humans and is one of two crocs known for attacking humans. More than 1,000 people are killed each year because of crocodile attacks.

1. Crows
   Seagulls
2. Geese
   Flamingos

If you've ever walked past a group of geese at your local park, you know these animals are territorial and are not frightened of humans. If you walk toward a group of geese, they will likely stand ground or even attack.

1. Dolphins
   Killer whales
2. Blue whale
   Beluga whale

Many people think great white sharks are the deadliest hunters in the ocean, but they have nothing on killer whales. Studies have shown great white sharks actually flee when they see killer whales encroaching the area. Like saltwater crocodiles and lions, no animal is silly enough to hunt a killer whale.

1. Wolverine
   Least weasel
2. Tasmanian devil
   Honey badger

Honey badgers are only aggressive when they get surprised, but their eyesight is so bad that they get surprised all the time. They are immune to most venom and have tough skin that gives them the courage to take on almost any animal.

1. Gorilla
   Baboon
2. Chimpanzee
   Black bear

Gorillas protect their young like their lives depend on it, and accidentally walking into their territory is a death sentence. They are one of the strongest animals on the planet but mostly eat bamboo, berries and stems.

1. Hyena
   Grey wolf
2. Domesticated dog
   Dingo

If you come across a wolf in the wild, it means you're likely surrounded by 15 other wolves you don't see. They rarely hunt alone, if ever, and they're one of the only animals crazy enough to hunt lions when in dire need.

1. Wild dog
   Dingo
2. Grey wolf
   Hyena

Hyenas are not related to dogs or cats or wolves. They are hyenas and they are one of the most unique animals in the world. There are four species of hyena, and the laughing variety is probably the most famous. Along with wolves, this is the only other animal silly enough to hunt a lion.

1. Mandrill
   Baboon
2. Gorilla
   Chimpanzee

Baboons, like most wild animals, can be extremely dangerous, but these guys are really dangerous when threatened. A baboon's fangs can be larger than a lion or tiger's, and they will readily attack under perceived threat.

1. Rhino
   Elephant
2. Giraffe
   Mastadon

The African elephant is under constant threat from poachers and hunters looking for a trophy. It is one of the "Big Five" game animals. They are peaceful animals, but when irritated or provoked, they can be one of the most dangerous in the world.

1. Tiger
   Lion
2. Jaguar
   Lynx

Tiger attacks have been well documented through history, and although there are more tigers in captivity than in the wild, they are capable of being just as aggressive in captivity. They are wild animals that can snap at any second are can never truly be tamed.

1. Panda bear
   Kinkajou
2. Koala bear
   Sun bear

The sun bear is found in Southeast Asia and is considered by many to be the most dangerous bear to encounter in the wild. That's because, like all bears, it will attack when threatened, but unlike other bears, it will also attack for no reason at all. You don't want to get caught in its territory.

1. Wolverine
   Least weasel
2. Honey badger
   Stoat

Mustelids are the smallest carnivores on the planet, and the least weasel is the smallest of the group, making it the smallest carnivore in the world. They create and defend large territories that consist of female areas and other animal's burrows.

1. Shrew
   Skunk
2. Rat
   Raccoon

A shrew is an insanely hyper rodent that spends the entire day hunting and eating. Its hunger is never satisfied, and because it has horrible eyesight, it literally runs around bouncing off the walls all day. It will eat almost anything it comes across.

1. Bull shark
   Hammerhead shark
2. Great white shark
   Tiger shark

The bull shark is known for living in shallow waters and is one of the most dangerous sharks to humans. It doesn't tolerate accidental encroachment in its territory, and it can be found in both saltwater and freshwater.

1. Peregrine falcon
   American eagle
2. Northern goshawk
   Golden eagle

These aren't the largest raptors in the sky, but they are known to prey on smaller hawks and are considered one of the most dangerous birds for other birds. They are also extremely territorial. They defend up to 10,000 acres from high above and attack any bird encroaching the area.

1. Bulldog ant
   Grasshopper
2. Cockroach
   Praying mantis

As far as humans are concerned, there's no insect as deadly as the mosquito, and the praying mantis poses no threat. As far as other insects are concerned, the praying mantis is the Boogey Man. These insects are expert hunters and can even take down animals as large as frogs and lizards.

1. Sea leopard
   Sea lion
2. Penguin
   Walrus

Sea leopards are also known as leopard seals and they have been known to play games of cat and mouse with penguins in the Arctic. Scientists don't even know why they do this, and they don't always eat the penguins they kill.

1. Honey badger
   Wolverine
2. Mongoose
   Shrew

Mongooses aren't aggressive toward humans and can even be kept as pets. Like a house cat, they will be extremely territorial and hunt and kill any rodent that encroaches on their territory. They are commonly used as rodent control pets. They're commonly believed to be immune to snake venom, but that's untrue.

1. Coral snake
   Rattle snake
2. Viper
   Inland taipan

The coral snake is one of the most venomous in the world, but since it lives most of its life burrowed underground, it isn't terribly aggressive. It is territorial if you happen to disturb its resting area.

1. Jaguar cichlid
   Tiger barb
2. Piranhas
   Rainbow shark

Piranhas love the smell of blood in water and are attracted to it like a magnet. They will also bite anything at least once when looking for food, making them some of the most aggressive aquatic animals.

1. Jaguar
   House cat
2. Tiger
   Lion

If you've ever seen a mouse get caught in a cat's territory, you know what comes next might possibly be the worst form of torture on Earth. There is strong evidence that domestic cats are responsible for a decline in songbird populations.

1. Pufferfish
   Giant snakehead
2. Tigerfish
   Lionfish

The giant snakehead or giant mudfish is known to be aggressive to humans who get too close to their nests. As far as other fish are concerned, the giant snakehead will attack and attempt to eat anything that can fit in its mouth.

1. Abispa
   Eastern cicada killer
2. Asian giant hornet
   Carpenter bee

If you don't like bees, you're not going to like this gigantic insect that has a three-inch wingspan and quarter-inch-long stinger. These bees can grow more than two inches long, and what makes them so aggressive is that they don't die or lose their stinger after they sting, they just keep stinging.

1. Viper
   Rattlesnake
2. Taipan
   Anaconda

There are three species of taipan. The coastal taipan is the most aggressive one and extremely venomous, but the inland taipan is the most venomous in the world. A single bite contains enough venom to kill 100 people or a quarter of a million mice. If you see any taipan, you should stay away.

1. Burgundy snail
   Garden snail
2. Cone snail
   Decollate snail

A snail's territory is its shell, and if you play with this snail's shell, it will get aggressive and sting you. These snails are venomous and their stings might not feel much more painful than a bee sting, but they do have enough venom to be fatal to humans.

1. Crpenter ant
   Bulldog ant
2. Pharaoh ant
   Fireant

If you don't like ants, you definitely won't like these ants that aggressively bite and sting. They got their name from their aggressiveness and have no fear of humans. They latch onto victims and sting in rapid succession as many times as possible.

1. Sea iguana
   Komodo dragon
2. Agama
   Chameleon

If you come face to face with one of these things in the wild, you really have to ask yourself how you got in that position. There's only 6,000 left on Earth and they're all located in the same area. Their venom is slow-acting, leaving them often trailing their bitten prey and waiting for it to die.

1. Peregrine falcon
   Cassowary
2. Ostrich
   Flamingo

If an ostrich feels threatened, it will likely run away, but if it feels cornered, it is one of the most dangerous birds in the world. At seven to nine feet tall and weighing in at 250 pounds, one kick from these birds can kill a lion, let alone a human.