1. Polar bear
   Gorilla
2. Reindeer
   Wildebeest

Polar bears are specifically built for living in the Arctic Circle. Not only do they have thicker fur and more fat, but polar bears also have large feet for maneuvering​ on ice and swimming.

1. Elephants
   Giraffes​
2. Impalas
   Lions

Lions live in family units known as prides. A pride usually consists of a few males along with around a dozen females and their young.

1. Octopus
   Humpback whale
2. Dugong
   Anaconda

Humpback whales are known for launching themselves out of the water before crashing back down, causing a huge splash. Scientists aren't sure why the whales display such behavior, though it could just be for fun.

1. Boa constrictor
   Komodo dragon
2. Crocodile
   Iguana

Crocodiles lurk in the water on the edges of river beds. When prey comes for a drink, they launch out of the water and pull their prey into the river with them. It's not a fun way to go.

1. Giraffe
   Leopard
2. Elephant
   Wildebeest

The African bush elephant is the largest animal found on land. These animals can live up to 70 years and grow to weigh around 13,000 pounds as an adult.

1. Wolf
   Tiger
2. Mongoose
   Fox

You won't find a bigger member of the cat family than the tiger. Though these enormous predators prefer to live alone, they sit at the top of the food chain, so other predators rarely mess with them.

1. Sea turtles
   Squids
2. Eel
   Stingray​

Sea turtles have been around for over 100 million years. These turtles are unique from others in that they can't retract their heads and limbs into their shells.

1. Zebra
   Bison
2. Elk
   Wildebeest

Wildebeest are migratory animals who travel for food and water. Millions of wildebeest take part in the migration each year along with several other animal species such as the zebra.

1. Wolf
   Black bear
2. Grizzly bear
   Gorilla

Though black bear attacks on humans are rare, they do occur. Humans are told to stand and face the bear if they see one and to never run away during an encounter.

1. Macaque
   Chimpanzee
2. Orangutan
   Lemur

Like humans, macaques are omnivores, meaning they eat both plants and meat. Common sources of meat include mice and birds.

1. Weasel
   Ferret
2. Wolf
   Opossum

A wolf pack is known for its strong social bond and ability to work together. Wolves have several sounds used to communicate over long distances with the pack.

1. Jellyfish
   Eels
2. Hammerhead sharks
   Great white sharks

Sharks are known for the thousands of razor-sharp​ teeth that cover their mouths. When a tooth falls out, it is replaced by another one from a different row. And no, they don't REALLY like to frighten swimmers!

1. Cheetah
   Boa constrictor
2. Rhinoceros
   African buffalo

Reaching speeds of 70 miles per hour, cheetahs are the fastest land animal on the planet. To make them even more dangerous, they can reach this speed in about three seconds.

1. Mongoose
   Giraffe
2. Grizzly bear
   Raccoon​

Grizzly bears go into a denning period during the winter. Leading up to this period, these bears consume as much food as possible to build fat to survive the winter.

1. Squirrel
   Groundhog
2. Prairie dog
   Owl

Owls possess large eyes and a flat face, providing them with excellent vision. These animals are able to turn their heads as much as 270 degrees.

1. Giraffe
   Zebra
2. Mule
   Donkey

Found in Africa, zebras are the relatives of horses and donkeys. All of these animals belong to the Equidae family.

1. Chimpmunk
   Ferret
2. Opposum
   Fox

Foxes have unique pupils which allow them to see in dim light. For this reason, foxes are typically active after the sun has set.

1. Jaguar
   Boa constrictor
2. Snapping turtle
   Elk

Jaguars might be predators, but they are vital for the ecosystem. Jaguars keep the population of plant-eating animals down, preventing overgrazing.

1. Water buffalo
   Gorilla
2. Scorpion
   Antelope

Gorillas are dived into two groups. In the mountains of central Africa, you will find the mountain gorilla while lowland gorillas live in the forest regions of central and western Africa.

1. Tapir
   Warthog
2. Reindeer
   Giraffe

Reindeer are also referred to as caribou in North America. These animals are known for their massive antlers which are grown by males and females.

1. Ferrets
   Chipmunks
2. Raccoons
   Squirrels

Though they are aggressive, raccoons live closely with humans. They can often be found digging through human garbage as they search for food.

1. Bison
   Moose
2. Dolphin
   Bonobo

A moose has a height of around six feet at the shoulders and can weight around 1,800 pounds. This makes them the largest deer species in the world.

1. Komodo dragon
   Anaconda
2. Boa constrictor
   Iguana

Komodo dragons use their long, thin tongues to detect where to find food. When food is found, the dragons rely on their sharp teeth and venomous bite to overcome the prey.

1. Crab
   Crayfish​
2. Oyster
   Stingray

The Australian zookeeper Steve Irwin spent much of his life teaching people about animals. Sadly, the man known as "The Crocodile Hunter" was killed by a stingray in 2006.

1. Orangutan
   Lemur
2. Chimpanzee
   Spider monkey

Orangutans have an arm width that vastly outsizes their height. An orangutan's arms can extend seven feet from fingertip to fingertip.

1. Ferret
   Opossum
2. Weasel
   Mink

When an opossum plays dead, it lets off a terrible odor to keep predators from taking a bite. Strangely, opossums don't choose when to play dead, but instead, fear drives their reaction.

1. Ferret
   Mink
2. Squirrel
   Groundhog

Groundhogs hide underground during the harsh winter months. During this hibernation period, their body temperature falls as their heart rate drops significantly.

1. Boa constrictor
   Python
2. Anaconda
   Kingsnake

Unlike many other snakes, anacondas give birth to live young instead of laying eggs. They can produce as many as 30 babies in a single litter.

1. Hyena
   Impala
2. African buffalo
   Warthog

If you've ever seen a warthog rolling in mud, it's probably cleaning itself of insects. These animals will also allow birds to ride on their backs, as the birds pick off insects in the process.

1. Tapir
   Giraffe
2. Koala
   Dingo

An adult male giraffe can stand as tall as 20 feet. This makes them the tallest mammals on the planet.

1. Panda
   Elk
2. Gibbon
   Wolverine

Pandas are hungry creatures and will spend as much as 12 hours a day eating. Luckily for them, 99 percent of their diet is composed of bamboo, which is common considering they live in bamboo forests.

1. Gibbon
   Koala
2. Kangaroo​
   Sloth

In a kangaroo society, the largest male dominates the group known as a "mob." Male kangaroos are known as "jacks," while females are called "jills."

1. Badger
   Sloth
2. Platypus
   Rhinoceros

Sloths aren't the most active or entertaining animals in the world. Hanging out in trees, these animals sleep around 20 hours a day.

1. Wombat
   Penguin
2. Koala
   Dingo

Koalas belong to the group of mammals known as marsupials. These mammals carry their young in a pouch for a time after birth as the young continues to develop.

1. Squirrel
   Otter
2. Hippopotamus
   Penguin

Penguins have relatives that are as old as 60 million years. That means that penguins outlived the dinosaurs.

1. Rhinoceros
   Dingo
2. Seal
   Dolphin

Rhinoceros is Greek for "nose horn." These animals have horns which are sought by poaching who acquire large sums of money on the black market because of the horn's use in traditional medicine.

1. Dolphin
   Squid
2. Octopus
   Hammerhead shark

Dolphins are social animals known for their playful nature. Their brains have evolved in a way that compares to that of a human.

1. Wombat
   Ferret
2. Wolverine
   Chipmunk

Wolverines are omnivores, but they prefer to eat meat. Not the largest predators, they hunt smaller prey but will feed on carcasses​ when they are available.

1. Jellyfish
   Octopus
2. Monkfish
   Frogfish

An octopus is quite the unique creature aside from its eight legs. This sea animal has three hearts that pump blue blood throughout its body. An octopus is also boneless, allowing it to move in the tightest of spaces.

1. Python
   Otter
2. Badger
   Hippopotamus

Hippopotamuses are extremely aggressive animals that aren't afraid to attack other predators. They are particularly dangerous if they are in or near the water.