1. Marmoset
   Spider Monkey
2. Baboon
   Howler Monkey

Spider monkeys are given their name because of their spider-like appearance when they hang from trees using their tails. In fact, their tails are so strong, they use them as an extra arm as they make their way through the dense vegetation and massive trees in the rain forest.

1. Sloth
   Anteater
2. Armadillo
   Lemur

Everyone's favorite super chilled out sloth can be found hanging out in Central and South America. They may be known for their hugs, but they're actually more of a solitary animal. Their bodies are home to small organisms like moths, beetles, and even fungi and algae.

1. Sperm Whale
   Beluga Whale
2. Blue Whale
   Humpback Whale

The blue whale is the largest animal to have ever lived on earth. To put this into perspective, their hearts can weigh as much as a car, and their tongues can weigh as much as an elephant! Even though they're gigantic, they feed on super small organisms in the ocean, like plankton and super small shrimp-like creatures called krill.

1. Cockatoo
   Parakeet
2. Cockatiel
   Macaw

Macaws are the largest of the parrot family. Some can span up to 3.5 feet in length, with a wingspan of up to 4 to 5 feet! There are around 20 species of the macaw, with many of them, unfortunately, being endangered and even critically endangered.

1. Weasel
   Mongoose
2. Meerkat
   Ferret

The mongoose can be found in parts of Africa, the Iberian Peninsula, and Asia. This feisty animal is frequently used to protect homes in India from poisonous snakes; the mongoose can withstand some venom from a snake if bitten, so that, coupled with its ability to fight, make it a formidable opponent for dangerous snakes.

1. Tasmanian Devil
   Koala
2. Dingo
   Kangaroo

The Tasmanian devil, who is in the same family as kangaroos, is the largest of the marsupials who eat meat. They have one of the most powerful bites in the world, which can crush through bones. They can even open their jaws up to 80 degrees. Imagine that coming at you!

1. Antelope
   Peregrine Falcon
2. Cheetah
   Quarter Horse

Many people think the cheetah is the quickest in the animal kingdom, but it's the peregrine falcon! They can fly up to 240 mph, which is about where even the fastest of supercars will top their speedometers. These falcons usually hit this speed when they are doing one of their classic dive bombs during a hunt.

1. Emu
   Rheas
2. Cassowary
   Ostrich

When they're not sticking their heads in the ground, ostriches can sprint up to 45 mph, with some of these birds even reaching up to 60 mph. While other animals are faster than the ostrich, its ability to hit these speeds make it the fasted animal on two legs.

1. Grizzly Bear
   Andean Bear
2. Sun Bear
   Cave Bear

While we do picture them being large and in charge, a mature grizzly can be as little as 250 pounds, which is smaller than some black bears. Most other species of bears typically weigh anywhere between 300 and 800 pounds. Still, there's no denying that this is an animal you do not want to mess with!

1. Leopard Seal
   Sea Lion
2. Manatee
   Walrus

While walruses do spend a large percentage of their time in the water, they prefer shallow water so they can easily access their food and maneuver themselves out of the water. Since they do live in the Arctic, which is primarily made up of ice, if a walrus can't get to a beach to sunbathe, it will hop on top of large pieces of ice that can support its weight and float on them.

1. Gray Wolf
   Jackal
2. Husky
   Red Wolf

While we can certainly think of some huge dogs like the Great Dane or Mastiff, the gray wolf is still officially considered the largest of the Canidae (dog) family. Adult gray wolves typically weigh around 75 – 125 pounds, with male wolves sometimes weighing up to 175 pounds. What makes them look even larger is their fur. During the winter, when it is fully grown out, their fur can get to be as long as 4 - 5 inches, making them look much taller and broader.

1. Vaquita
   Porpoise
2. Ganges River Dolphin
   Dolphin

The porpoise, who looks a lot like the dolphin, is the smallest of the cetacea order, which includes dolphins and whales (though, it's easy for just about anything to be small compared to a whale!). The way you can tell a porpoise apart from a dolphin is primarily by their smaller size, but they also have a rounder body shape and a lack of the "beak" we see on dolphins.

1. Siberian Tiger
   Sumatran Tiger
2. Malayan Tiger
   Bengal Tiger

Bengal tigers are the only species that will sometimes grow white fur instead of the orange and black coat we know so well. This is because of a lack of the pigment pheomelanin. Compared to the orange Bengal tiger, the white Bengal can grow to be even faster and heavier than the orange.

1. Alligator
   Caiman
2. Gharial
   Crocodile

It has been argued for decades whether or not the crocodile is a "living fossil," but the reality is this animal has lived through the multiple mass extinctions that wiped out dinosaurs and other mammoth creatures across the planet. Fossil records show they have maintained the same body form through all of this time, giving them the name "living fossil."

1. King Cobra
   Rattlesnake
2. Inland Taipan
   Copperhead

While all of the above snakes are highly dangerous and poisonous, none of them deliver the amount of venom (or death) that the inland taipan can. Each one of their bites can deliver up to 110 mg, which is powerful enough to kill 100 adult men or 250,000 mice. If left untreated, a bite from this snake could kill a person in 45 minutes.

1. Crowned Eagle
   Harpy Eagle
2. Bald Eagle
   Golden Eagle

The above eagles are all considered to be among the world's most powerful birds, but the harpy eagle reigns supreme among them. Their talons alone are the same size as a grizzly bear's at 3 - 4 inches long! Harpy eagles can grow to be nearly 4 feet long, with a wingspan of up to 7.5 feet.

1. Echidna
   Porcupine
2. Hedgehog
   Armadillo

The quills on a porcupine are purely there as a defense system. While they can not project them from their body, they are easily removed when brushed up on by a predator. What makes them sting is the fact that they're barbed, making it very hard for removal once stuck in the skin. Hedgehogs also have quills, but these are considered hollow hairs that are made stiff with keratin. They do not easily detach from their bodies, and they will not stick into the skin of someone who touches them.

1. Fruit Bat
   Vampire Bat
2. Bulldog Bat
   Leaf-nosed Bat

Fruit bats are among the largest species of bats in the world, and they get their name, "flying fox," because of their cute, furry, fox-like faces. These flying critters eat only fruit juice, fruit pulp, and small insects, including mosquitoes. Even though they are harmless and will never typically attack humans, it is advised against trying to touch one; with their high diet of mosquitoes, they are known to carry the rabies virus.

1. Wombat
   Sugar Glider
2. Wallaby
   Kangaroo

Mama kangaroos take into account the chances of survival of their young based on environmental factors and other surrounding circumstances, and if they think chances are low, they will slow down the gestation period. And get this, not only can they slow the growth of their baby, but they can also determine its sex!

1. Black Lemur
   Ring-tailed Cat
2. Ring-tailed Lemur
   Raccoon

There are 32 species of lemur in the world, and of them, the ring-tailed lemur is the most popular. Much like the movie, you can only find them in nature in Madagascar, but you can still see them in zoos all over the world. While they are technically endangered in the wild, many are bred in captivity to thwart the many threats against its survival.

1. Coyote
   African Wild Dog
2. Hyena
   Maned Wolf

While the scientific name for the African wild dog means "painted wolf," it is more casually known otherwise as the painted hunting dog. No two wild dogs will ever have the same markings, making them easily identifiable by their individual "fingerprints."

1. Mexican Bearded Lizard
   Iguana
2. Komodo Dragon
   Gila Monster

Komodo dragons, who are now very hard to find in the wild, are the largest lizards currently living. They can grow to be 10 feet in length and weigh a whopping 200 pounds. They are as fierce as they look and are excellent hunters who like to prey on animals like pigs, deer, and even water buffaloes. Adding to their ferocity is their ability to inject venom when they bite into their prey.

1. Honey Badger
   Ferret
2. Skunk
   Meerkat

Meerkats will live in groups of up to 40 or 50 animals. Within these groups, there will always be a sentry, or lookout, to keep an eye out for predators while the others forage for food or build their burrows. The structure of these groups is also matriarchal, meaning that an alpha female is the one to lead them.

1. Rhinoceros
   African Elephant
2. Giraffe
   Hippopotamus

Everyone's favorite gentle giant is truly that ... a giant! The average African elephant can grow to up to 13 feet tall and weigh up to 14,000 pounds. Males are usually the ones who will grow to be this size, with the females being significantly smaller. African elephants are considerably larger than Asian elephants; even their ears are bigger and resemble the shape of Africa!

1. Blue Whale
   Sea Turtle
2. Tortoise
   Dolphin

While many tortoises will have a life span that is somewhat comparable to that of a human's, a large percentage of them have been found to live well past 150 years, up to 200. You can get a decent idea of how old a tortoise is by counting the rings on the top of their shell, just like you would with the inside of a tree.

1. Armadillo
   Hedgehog
2. Tenrec
   Porcupine

The armadillo's name is an appropriate one. Their shells are so strong that there have been reports of people injuring themselves after trying to shoot one-- the bullets ricochet off the armadillo's shell and hit the person. That's crazy! While their shells are incredible sources of protection, they can also tell us the armadillo's species is (there are 20).

1. Beaver
   Mallard
2. Otter
   Platypus

A platypus' bill is made of up thousands of cells that somehow give it an extra sense, especially when it is under water. When they dive, they become sightless and cannot smell, so they use their beak to navigate and to hunt for food.

1. Emu
   Elephant Bird
2. Vulture
   Golden Eagle

The soft, fluffy emu is indeed the second largest bird in the world. While an ostrich can weigh between 220 and 350 pounds, an emu will weigh between 90 and 150 and can grow to be up to 6.5 feet tall. Still very big for a bird! Just like an ostrich, the emu is flightless but will beat you in a foot race with its powerful legs.

1. Fennec Fox
   Arctic Fox
2. Gray Fox
   Red Fox

The Arctic fox is also known as the white fox or snow fox and is highly-adapted to living in frigid environments. Its super thick fur helps keep it warm in the winter and will also act as a camouflage; in the spring, you'll see Arctic foxes sporting more of a brown fur, and as soon as the winter comes, their white coat will come back in.

1. Orangutan
   Chimpanzee
2. Bonobo
   Gorilla

Orangutans share 97% DNA with humans, and much like us, they are highly capable of using tools and can even communicate through sign language. What sets them apart from other primates is their ability to learn from demonstration. Whether it is using soap, using a specific tool, or using a damp rag to cool themselves, they're able to learn more quickly and remember what they've learned compared to other primates (and let's face it, some humans!).

1. Seahorse
   Pacific Tree Frog
2. Mimic Octopus
   Chameleon

The chameleon's most outer layer of skin is transparent and underneath that, are several layers that contain cells called chromatophores. These are what allow them to change color; they are filled with sacs of different pigments that reflect different colors. Much of why a chameleon will change its color is not always because of its surroundings but could be because of its body temperature or even its mood.

1. Anteater
   Aardvark
2. Armadillo
   Sloth

This is no lie, the anteater's tongue is 2 feet long! It starts back at their breastbone and is covered in backward-facing spines and sticky saliva, perfect for scooping up ants and termites. With how long their tongue is and how it works, they're able to slurp up hundreds of ants at a time. What's especially interesting is that anteaters don't have teeth.

1. Rhinoceros
   Lion
2. Giraffe
   Zebra

It may be the tallest animal on earth, but they are still hard to spot, even if you go on a safari. For one, their distinctive markings are great for camouflage, but they also are not likely to just come right up to you in the wild. If they do, they are known to be quite friendly and will take food from you with their gigantic tongues.

1. Wolverine (Skunk Bear)
   Brown Bear
2. Polar Bear
   Black Bear

The black bear's size will vary quite a bit between male and female; males can weigh up to 400 pounds, while females will only weigh up to 175 pounds. What primarily makes them seem so much smaller is that they typically are only about 3 feet tall when they are on all fours and around 5 to 7 feet when they are standing upright. These bears may be shorter than some people, even when upright.

1. Crow
   Rat
2. Pigeon
   Squirrel

Pigeons have been able to so successfully live in cities due to their ability to turn just about any ledge, crevice, or nook into a hospitable environment for their nests and shelter. It sure helps them out knowing they can rely on humans dropping scraps and voluntarily feeding them!

1. Harp Seal
   Otter
2. Mink
   Sea Lion

Otters have two thick layers of fur; they have an undercoat and then the longer hairs that are much more visible. Altogether, an otter will have up to one million hairs per square inch. All of this fur helps keep them dry in the water and helps them float by trapping air in between the two layers.

1. Boa Constrictor
   Ball Python
2. Green Anaconda
   Kingsnake

There are some big snakes in the world, but the green anaconda is by far the largest. These snakes can grow to be 29 feet in length and weigh 550 pounds! They are non-venomous and contrary to what we've seen in the movies, they are not known to eat humans.

1. Panther
   Leopard
2. Lion
   Jaguar

The jaguar can only be found in North, Central and South America. In North America, they primarily dwell in Texas, Arizona, New Mexico and Southern California. However, the largest population of them can be found in the Amazon rain forests. The jaguar is the third largest of the big cats and the largest of all the big cats you'll see in the Americas.

1. Red Wolf
   Coyote
2. Hyena
   Gray Wolf

You can find coyotes all over the country, but you will mainly see them near cities in states like Colorado, New Mexico, Arizona, and Texas. Often they carry the reputation of being a pest, but in reality, they can help with population control of other problematic animals, like rodents.

1. Tiger Shark
   Hammerhead Shark
2. Great White Shark
   Whale Shark

They may be huge and very intimidating, but whale sharks will never attack humans. Much like whales, they feed on tiny micro-organisms by swimming slowly through the ocean and filtering out creatures like plankton and krill with their teeth. They are extremely docile and are even accustomed to swimming alongside humans.