1. Chipmunk
   Squirrel​
2. Hamster
   Mouse

Constantly hunted for food, mice rarely live longer than six months in the wild. However, mice that are used for science experiments, which is quite common, can live close to two years.

1. Pig
   Frog
2. Cow
   Donkey

Pigs have become synonymous with rolling in the mud, an act they perform to cool off. However, despite their love of the dirt, pigs are actually quite clean. If they are left in clean conditions, they will actually avoid the mud.

1. Iguana
   Turtle
2. Gecko
   Alligator

Turtles are reptiles that have been around for millions of years. Some turtles will lay eggs then abandon them, leaving the young to fend for themselves once they hatch. Sadly, most of those hatchlings do not survive long.

1. Hippopotamus
   Rhinoceros
2. Elephant
   Giraffe

Recognized by their long tusks and floppy ears, there is no larger land animal than the elephant. These massive creatures can grow up 13 feet high and weigh as much as 14,000 pounds.

1. Wildebeest
   American buffalo
2. Bull
   Camel

Having developed in the desert, camels are specifically designed to combat the harsh conditions you'll find there. One such characteristic that helps them is that they have three eyelids which keep​ sand out.

1. Friesian horse
   Thoroughbred
2. Fjord horse
   Breton horse

Thoroughbreds are native to England, where they were developed beginning in the 17th century. This breed of horse is a cross between a mare and a stallion with a combination of power, speed, and agility.

1. Grizzly bear
   Moose
2. Bull
   Camel

Living as solitary animals, grizzly bears prefer to be left alone if possible. However, large quantities of these animals do gather along Alaskan fishing spots to feast together during the ​salmon season.

1. Panther
   Leopard
2. Lion
   Tiger

Weighing as much as 600 pounds, you will not find a bigger cat out there than the tiger. In fact, when it comes to size, tigers are the third-largest carnivore that lives on dry land.

1. Raccoon
   Polar bear
2. Wolf
   Fox

Wolves are excellent at communicating with one another, using several different sounds to mean different things. These sounds are particularly helpful on hunts where wolves separate and surround their prey.

1. Salamander
   Gecko
2. Crocodile
   Iguana

Iguanas are cold-blooded creatures, which means they like to hang out in warm places to keep their body temperature up. For people who keep them as pets, heat lamps are often required for iguanas to stay warm.

1. Panda
   Polar bear
2. Koala
   Sloth

Panda bears are found throughout the mountains of central China where bamboo is abundant. These animals will spend up to 12 hours a day stuffing their stomachs, mainly with the bamboo.

1. Deer
   Moose
2. Elk
   Alpaca

Male deer are recognized by the large pair of antlers that grow out of their heads. These deer will shed their antlers once a year just to grow them back. The antlers can grow around 200 inches in only 120 days.

1. Opossum
   Chipmunk
2. Squirrel
   Raccoon

Raccoons are extremely adaptable animals that can be found anywhere from forests to prairies to cities. They have a very wide diet, including frogs, mice, nuts, and berries.

1. Sheep
   Cheetah
2. Lion
   Coyote

Reaching speeds up to 70 miles per hour, you won't find a faster land mammal than the cheetah. These quick creatures can hit that top speed in as little as three seconds, which is pretty scary for prey.

1. Cat
   Hamster
2. Iguana
   Fox

Though they are common house pets where they are kept in cages, hamsters can also live in burrows in the wild. These burrow lovers are nocturnal animals, as well, meaning they hunt at night.

1. Camel
   Giraffe
2. Pig
   Goat

With legs that run about six feet in length, you won't find a mammal on earth taller than a giraffe. These animals will commonly use their length to pick food out of the highest branches of trees.

1. Alligator
   Rhinoceros
2. Hippopotamus
   Wildebeest

With a name derived from the ancient Greek word for "river horse," hippopotamuses are extremely aggressive animals. When confronted by a predator, they will use their large teeth to scare them off.

1. Wildebeest
   Zebra
2. Gazelle
   Rhinoceros​

Each year, millions of wildebeest travel hundreds of miles across Africa in what is known as the Great Migration. They are joined by thousands of zebras and gazelles​ on this journey.

1. Opossum
   Llama
2. Squirrel
   Beaver

Opossums tend to mate twice a year, with the male leaving as soon as the mating is finished. The babies are born in about 12 days, then they are raised in their mother's pouch until they are fully developed.

1. Donkey
   Cow
2. Sheep
   Ram

If you run across a sheep in the wild, they tend to be a larger size than their domesticated counterparts. Aside from their size, they grow much longer horns that are used for defense.

1. Anteater​
   Sloth
2. Opossum
   Armadillo

The official state animal of Texas, armadillos are covered in overlapping plates that resemble armor. These protective plates, which are made of dermal bone, cover their entire bodies from head to tail.

1. Mouse
   Hampster
2. Dog
   Cat

An adult dog has nearly the same brain capacity as a two-year-old toddler. If trained correctly, they can memorize around 250 words and commands. Some of the most common commands are sit and shake.

1. Water buffalo
   Rhinoceros​
2. Lion
   Bull

Led by a dominant male, lions tend to live in a pride where they prefer to hunt in packs. Prides consist of lesser dominant males, females, and their offspring. Often, the dominant male will kill off the offspring of other males.

1. Bull
   Cow
2. Donkey
   Llama

Traditionally, donkeys were used as labor animals, capable of hauling much more than a human. They were commonly used on farms where they plowed the land. They could be quite stubborn, however, if an owner didn't know how to handle them.

1. Impala
   Hyena
2. Zebra
   Gazelle

Three hyenas appear as villains in the movie "The Lion King," where they work under the antagonist, Scar. Their names are Banzai, Shenzi, and Ed, and they are depicted as being quite clumsy and unintelligent. This is not the case for hyenas in real life.

1. Tasmanian devil
   Wombat
2. Koala
   Porcupine

Found all across the world, porcupines live between five and seven years in the wild. Their main form of defense is​ their quills, which easily detach and regrow. Despite the common misconception, quills cannot​ be shot at a predator.

1. Squirrel
   Bull
2. Porcupine
   Rabbit

Rabbits have different names based on their gender and age. For example, a male rabbit is called a buck, and a female rabbit is referred to as a doe. A baby rabbit, for both sexes, is called a kit.

1. Sloth
   Fox
2. Dhole
   Dingo

Part of the Canidae family, foxes differ from their relatives in that they are not pack animals. Instead, foxes prefer to live solitary lives, except when they are raising their young.

1. Polar bear
   Koala
2. Wombat
   Sloth

Polar bears are found throughout the Arctic, where weather conditions are freezing. Luckily, polar bears have a thick layer of blubber and fur to protect them from the harsh conditions.

1. Alpaca
   Stegosaurus
2. Bison
   Rhinoceros

Rhinos possess horns that are highly sought after on the black market. For that reason, these animals have been hunted to near extinction, but conservation efforts have ramped up significantly to protect them.

1. Bison
   Oxen
2. Gazelle
   Llama

Found throughout the Andes Mountains in South America, llamas are close relatives to the camel. These animals have been domesticated by people in the Andes and are commonly used for transporting supplies.

1. Moose
   Elk
2. Reindeer
   American buffalo

You won't find a bigger member of the deer family than the moose. These creatures tower to around seven feet at the shoulders and can weight up to 1,500 pounds. They also have massive antlers that, similar to deer, will fall off each year.

1. Fox
   Coyote
2. Dingo
   Wombat

Found throughout the mountains and forests of North America, coyotes are extremely smart animals with heightened senses. They are also quite territorial and use their urine to mark out their territory.

1. Beaver
   Squirrel
2. Chipmunk
   Prairie​ dog

Beavers are semi-aquatic rodents with webbed feet and covered in thick fur. They also have long teeth capable of chewing through wood, which they use to build their homes along rivers.

1. Lynx
   Jaguar
2. Oxen
   Elk

When it comes to felines, jaguars fall only behind the lion and the tiger in terms of size. They can be found throughout North and South America where they feed on everything from deer to crocodiles.

1. Alpaca
   Gazelle
2. Bison
   Oxen

Bison once lived in vast abundance all across North America, where they were commonly hunted by Native Americans. During the 19th century, they were hunted to the point of near extinction, but luckily, their numbers have rebounded since then.

1. Fox
   Jackal
2. Coyote
   Mountain lion

Jackals are found primarily in Africa, where they can be found in three different species. These species include the black-backed jackal, the common jackal, and side-striped​ jackal.

1. Chameleon
   Salamander
2. Crocodile
   Alligator

Alligators are often confused with crocodiles, which is a close relative. However, alligators have rounded, U-shaped snouts, where crocodiles have much more narrow, V-shaped snots.

1. American buffalo
   Gazelle
2. Bull
   African buffalo

Bull-riding is an adventurous but very dangerous sport that hundreds of people engage in yearly. Injuries are quite common as bulls are judged by how fast they can buck off a rider.

1. Poison dart frog
   Tree frog
2. American bullfrog
   Fire-bellied toad

Reaching up to eight inches in length, female bullfrogs are usually larger than their male counterparts. Both sexes are excellent swimmers with long back legs and wide webbed feet.