1. Sloth Bear
   Polar Bear
2. Grizzly Bear
   Black Bear

Sloth bear cubs between 6 and 9 months old cling to an extra patch of fur on the sloth mother's back. The sloth bear does not have an undercoat beneath its fleecy fur, which keeps the bear cool in their tropical environments.

1. Gray Tree Frog
   African Clawed Frog
2. Coronated Tree Frog
   Golden Mantella Frog

The coronated tree frog is monotypic of the genus Anotheca. Although it has no vocal structures, the repetitive sounds it makes can be heard up to 300 feet in the distance.

1. Great Horned Owl
   Barred Owl
2. Burrowing Owl
   Australian Masked Owl

Minnesota, the "land of 10,000 lakes," has several types of owls, but the great horned owl is the most prevalent in the state. This owl makes a piercing shrill and emits a booming "hoot."

1. Banded Rock Rattlesnake
   Eastern Diamondback Rattlesnake
2. Eastern Indigo Snake
   Lance Head Rattlesnake

The Eastern diamondback rattlesnake is the longest snake in all of North America. This husky breed averages 10 pounds.

1. Blue-Tongued Lizard
   Collared Lizard
2. Caiman Lizard
   Chinese Crocodile Lizard

The Chinese crocodile lizard can only be found in Asia, specifically in Vietnam and China. This lizard earned the nickname "lizard of great sleepiness" because it often enters a catatonic state for up to several hours at one time.

1. Stellar Sea Lion
   South American Sea Lion
2. Galapagos Sea Lion
   Australian Sea Lion

You'll find the largest population of Australian sea lions in Kangaroo Island and Dangerous Reef in South Australia. Certain colonies of the endangered Australian sea lion are protected by the Great Australian Bight Marine Park.

1. Nile Crocodile
   Cuban Crocodile
2. Saltwater Crocodile
   Philippine Crocodile

The Cuban crocodile roams the smallest range of any crocodile. This crocodile typically ventures no farther than 200 square miles.

1. Black Howler Monkey
   Allen's Swamp Monkey
2. Titi Monkey
   Goeldi's Monkey

To fortify social bonds, titi monkeys entwine their tails when they sit together. This occurs whether the monkeys are asleep or awake,

1. Northern Elephant Seal
   Northern Fur Seal
2. Gray Seal
   Harbor Seal

The North Pacific-dwelling northern elephant seal is the second largest seal in the world, with adult males averaging 4,500 pounds. The southern elephant seal is the world's largest seal.

1. Red-Crowned Crane
   Whooping Crane
2. Hooded Crane
   White-Naped Crane

The white-naped crane is found in Mongolia. This wild crane species stands approximately 44 to 49 inches in height.

1. Aldabra Tortoise
   Impressed Tortoise
2. Radiated Tortoise
   Red-Footed Tortoise

The wild radiated tortoise fancies the woodlands, thorn forests and dry brush regions of southern Madagascar. This slow-moving tortoise prefers the solitary life and is most active during the daylight hours.

1. Black-and-White Ruffed Lemur
   Red-Fronted Lemur
2. Red-Ruffed Lemur
   Ring-Tailed Lemur

The wild ring-tailed lemur is known for its distinctive long tail, which measures close to 23 inches. These creatures have white underbellies, feet and hands.

1. Chacma Baboon
   Gelada Baboon
2. Olive Baboon
   Yellow Baboon

Gelada baboons are very terrestrial creatures. Most of them prefer to occupy open plateaus and near the clefts and steep slopes that surround these areas.

1. American Badger
   Eurasian Badger
2. Japanese Badger
   Honey Badger

The honey badger tends to strike only when startled by predators. This badger's skin is so thick that it can withstand porcupine quills and bee stings.

1. Killer Whale
   Long-Finned Pilot Whale
2. Southern Right Whale
   Baleen Whale

Adult male killer whales are massive, and can grow as large as 9 meters in length on average. Adult female killer whales grow as large as approximately 8 meters in length.

1. Barasingha Deer
   Eld's Deer
2. White-Tailed Deer
   Larger Malay Mouse-Deer

A standing larger Malay mouse-deer's hind pair of legs rise higher than its front end. This nocturnal creature is usually found in south Asia.

1. Eastern Box Turtle
   Florida Box Turtle
2. Chinese Three-Striped Box Turtle
   Gulf Coast Box Turtle

The Gulf Coast box turtle is the largest of the box turtles. The largest size of a Gulf Coast box turtle ever recorded is 8.5 inches.

1. Sand Cat
   Fishing Cat
2. Ocelot
   Serval

In South America, only the jaguar is larger than the ocelot. The endangered ocelot weighs 30 pounds and is approximately 4 feet long.

1. Southern Two-Toed Sloth
   Pale-Throated Three-Toed Sloth
2. Hoffman's Sloth
   Giant Ground Sloth

The oldest living sloth died at 49 years old and was a two-toed sloth. In the wild, a two-toed sloth's lifespan is 20 years on average.

1. Raccoon Dog
   African Wild Dog
2. Bush Dog
   Black-Tailed Prairie Dog

The fleeting bush dog is hard to observe in its Central and South American tropical environments. Their lifespan in the wild is unknown.

1. Green Tree Python
   Timor Python
2. Burmese Rock Python
   Carpet Python

The Southeast Asian Burmese rock python is a crossbreed of the Indian python. It can disconnect its jaw to devour prey four to five times the size of its head.

1. Golden Eagle
   Crowned Eagle
2. Tawny Eagle
   Bald Eagle

The bald eagle is found throughout North America. Its lifespan is approximately 50 years.

1. Dwarf Mongoose
   Small Indian Mongoose
2. Yellow Mongoose
   Javan Gold-Spotted Mongoose

The dwarf mongoose is native to eastern and South Africa. This omnivore may have a vast diet, but a full-grown male weighs approximately 11 ounces.

1. Barking Gecko
   Giant Leaf-Tailed Gecko
2. New Caledonian Gecko
   Tokay Gecko

The New Caledonian gecko is exclusive to the South Pacific islands of New Caledonia. The New Caledonian gecko can release its tail if it is distressed and grow it back later.

1. African Clawless Otter
   Giant Brazilian Otter
2. Marine Otter
   Sea Otter

The marine otter weighs approximately 13 pounds, while the sea otter weighs an average of 100 pounds. The marine otter dwells in South America along the Pacific coast region.

1. Black-Jacked Jackal
   Golden Jackal
2. Side-striped Jackal
   Silver-Backed Jackal

Recent biological analysis has revealed that the African golden jackal differs from the gray wolf in mitochondrial DNA up to 6.7 percent. A small population of this slightly diverse gray wolf subspecies can be found across North and East Africa.

1. Australian Pelican
   Eastern White Pelican
2. Great White Pelican
   Brown Pelican

The plunge-diving brown pelican has air sacs all over its body to protect it from impact. It uses its huge bill sack underwater to scoop up prey like a fishing net.

1. Chilean Rose Tarantula
   Goliath Bird-Eating Tarantula
2. Pink-Toed Tarantula
   Salmon Pink Bird-Eater Tarantula

The Goliath bird-eating tarantula is the largest spider in the world. It can weigh up to approximately 6 ounces.

1. Bat-Eared Fox
   Fennec Fox
2. Arctic Fox
   Asian Red Fox

The small fennec fox is native to the dry regions of Arabia and North Africa. This fox is an excellent jumper, even though mature adults can only grow as long as 16 inches on average.

1. Sulfur-Crested Cockatoo
   Red-Tailed Cockatoo
2. Roseate Cockatoo
   Long-Billed Cockatoo

Roseate Cockatoos are rather noisy when flocking in groups. These birds prefer to graze the open grasslands of Australia for seeds and grain.

1. Northern Bettong
   Woylie
2. Boodie
   Eastern Bettong

The woylie is considered a brush-tailed bettong because it has a black brush at the end of its long tail. This wild nocturnal creature forages the native fungi of Australia.

1. Blue Catfish
   Black Pacu
2. Arapaima
   Channel Catfish

The meaty blue catfish can weigh up to 115 pounds! This fish is native to the freshwater rivers of Mississippi, Ohio and Missouri.

1. Lesser Flamingo
   Greater Flamingo
2. American Flamingo
   Andean Flamingo

The American flamingo is also known as the Caribbean flamingo. Of all the flamingo species, the American flamingo is a more intense hunter. It submerges its entire head and much of its neck into lagoon waters to catch prey.

1. Corn Snake
   False Water Cobra
2. Gaboon Viper
   Green Anaconda

In spite of its size and reputation for attacking humans on sight, anacondas are rarely hostile toward humans. A large full-grown anaconda can weigh as much as 1,100 pounds and can measure as large as 12 inches in diameter.

1. Eastern Wolf
   Common Wolf
2. Gray Wolf
   Red Wolf

Populations of gray wolf, also known as the timber wolf, have experienced decline due to change in habitat. In the past, the gray wolf roamed more than two-thirds of the United States.

1. Beisa Oryx
   Scimitar-Horned Oryx
2. Fringe-Eared Oryx
   Taurotagus oryx

The eland is most commonly found on game reserves in South Africa. This animal has a small hump on its back and loose-hanging skin under its neck, which is called a dewlap.

1. Fairy Penguin
   Galapagos Penguin
2. Little Blue Penguin
   Magellanic Penguin

The Galapagos penguin is the only penguin that inhabits the equator. These wild creatures hop with two feet and waddle as they move about.

1. Black-Collared Barbet
   Crested Barbet
2. Barrow's Goldeneye
   White-Rumped Vulture

The white-rumped vulture is a critically endangered species due to population decline. Scientists have concluded that veterinary use of non-steroidal anti-inflammatory drugs (NSAIDs) in animals is causing the rapid decline of the animal carcass-scavenging white-rumped vulture.

1. Rock Pigeon
   Canada Goose
2. Bahama Pintail
   White-Cheeked Pintail

Canada Goose is the name of a luxury apparel company founded in Toronto, Canada. Canada geese are very popular birds. These birds form a recognizable V-shape as they emit honking noises while flying through North American skies.

1. Bobcat
   Caracal Lynx
2. Cheetah
   Clouded Leopard

The bobcat is able to run up to 30 miles per hour. This wild animal is an extremely skilled hunter. The bobcat can place its hind feet in the same position as its front feet to reduce noise during a hunt.