1. Whale Sharks
   Horse Chickens
2. Rat Dogs
   Lion Eagles

Standing up to 11.8 inches tall, whale shark eggs are the biggest eggs. However, there is a twist. Whale sharks do not lay their eggs. Instead, whale sharks hold the eggs inside until they hatch.

1. The Blue Whale
   Cheetah
2. Elephant
   Woolly mammoth

Yes, it swims, but it's still a mammal. That means it has live young and warm blood, and it breathes air (as opposed to using gills).

1. The Great White
   Hammerhead
2. Wobbegong
   Thresher

It was made famous in "Jaws" and has a massive bite. That said, it probably doesn't want to bite you, because it doesn't go near the shore very often.

1. Insects
   Arachnid
2. Arthropod
   Invertebrate

Insects are a member of the athropod phylum, which also includes myriapods and crustaceans.

1. Arachnids
   Chelicerata
2. Myriapoda
   Tetrapulmonata

Arachnids are, like insects, a part of the athropod phylum, and join it in rounding out the phylum along with myriapods and crustaceans.

1. Spiders
   Worm
2. Tiger
   Lyrebird

Spiders have amazing abilities, including making silk fibers so strong they can stop a bullet. They're actually being used in military experiments as an alternative to Kevlar.

1. Horses
   Cats
2. Dogs
   Fish

Dogs and humans have been cooperating for many thousands of years, and it has certainly been very good for both species!

1. Chimp
   Gorilla
2. Macaque
   Bonobos

Bonobos are not only the most genetically similar, they also have a lot in common with us socially (or at least, with some of us), being fairly egalitarian and open-minded.

1. Jaguar
   Lion
2. Mountain lion
   Cheetahs

A cheetah has been clocked at up to 75mph for short bursts, making it the fastest cat and also fastest land animal.

1. Prairie vole
   Naked mole rats
2. Nematode
   Jellyfish

While some species could, in theory, just keep on growing forever, like jellyfish, and their age is hard to discern, the naked mole rat is the only one that shows no sign of its age.

1. Girafffe
   Camel
2. Leopard
   Mountain lion

The name came about because giraffes have camel-like stature and leopard-like coloring. Their current -- much better -- name is Spanish and Portuguese in origin.​

1. Armed spider
   Cellar spider
2. Orb-weaver spider
   Trap door spider

While webs are mainly about catching prey, they're also for hiding yourself - if you are the wily trap door spider!

1. Scorpion
   Human (I hope!)
2. Rattlesnake
   Lizard

A snake doesn't want to get in your boot, but a scorpion may like the look of it and be just as dangerous. So always shake your boot before you put it on.

1. Seahorse
   Man o' war
2. Seal
   Anemone

This famously deadly jellyfish is actually two individual polyps that are technically separate creatures, but work together inside one jelly shell!

1. Monkey
   Flying squirrel
2. Wombat
   Bats

Bats actually don't all use echolocation, as they have very good eyesight - but those who do use it, do so masterfully.

1. 150 years
   100 years
2. 250 years
   50 years

A good run for one of these beautiful creatures is 150 years, but Jonathan of St. Helena in the Atlantic is 183 and going strong!

1. 10 lbs
   25 lbs
2. 5 lbs
   2 lbs

Due to a giraffe's unique shape, its massive heart is absolutely necessary for pumping blood all the way up its neck. Even when prone, a giraffe's resting blood pressure is 280/180 mmHg,.

1. Pilot whale
   Blue whale
2. Sperm whale
   Grey whale

The only mammals that stop breeding long before death are humans, killer whales, or pilot whales. While many other mammals experience menopause, none of them live very long after their reproductive years are behind them, meaning, for them at least, menopause is death.

1. Brazilian wandering spider
   Tarantula
2. Recluse spider
   Huntsman spider

This is the most venomous spider, but fortunately you won't encounter it unless you are in Brazil or parts of Central America.

1. Frogs
   Fish
2. Whales
   Dolphins

As tadpoles, frogs breathe through gills, but as adults they breathe through their nostrils!

1. They are used for cooling.
   They gather sounds better.
2. They sense vibrations in the air, an early warning about predators.
   They are used to swat away insects.

Elephant ears are full of blood vessels and serve to cool the body of the elephant by cooling its blood supply.

1. 40-50 years
   10-20 years
2. 20-30 years
   80+ years

Gorillas, those intelligent, burly cousins of ours, have pretty good lifespans for creatures that lack the benefits of medicine. It could be their 100 percent vegetarian diet, or it could be that they live very stress-free lives. It's probably just built into their genes.

1. 70 mph
   50 mph
2. 100 mph
   200 mph

When they dive to kill their prey by striking with their skulls, peregrine falcons can reach 200 mph. This means that when stalking other birds, these predators can shatter other birds' spines with a single blow. Ouch.

1. It is female.
   It is hungry.
2. It is angry.
   It's honestly just kind of a jerk.

Male mosquitoes do not bite, leaving the blood-sucking reputation of their species to female mosquitoes. Recent studies have shown that, because mosquitoes are averse to strong vibrations, one way to ward them off is to wave at them, even if you don't hit them. Really? Did they need​ a study to figure out that strategy?

1. Hair
   Nails
2. Skin
   Teeth

Rhinoceros horns are composed of keratin, the same substance that your hair and fingernails are made of. Rhino horns form from hair that grows and tightly compacts, bonding to itself, over a rhino's lifetime. Inside this ball of keratin sit mineral deposits of calcium and melanin, which keep the horn hard and pointy, while protecting it from deterioration from sunlight. In many nature preserves, rhinos are relieved of their horns by conservationists in order to discourage poachers from killing these great beasts for the bit of hair on the ends of their noses. Crazy, right?

1. Horses
   Dogs
2. Rats
   Wallabies

Horses and cows both sleep standing up. Both of these animals are prey species, and have evolved so they can awaken and run to safety should a predator turn up. As a result, visiting a farm at night would mean seeing lots of large animals that seem awake, but aren't.

1. Cow
   Sheep
2. Goat
   Pig

The myotonic goats faint and fall over when they are surprised. It's hilarious but also rather sad as naturally it makes them quite vulnerable to predators.

1. Gorilla
   Collie
2. Parrot
   Dolphin

​The smartest collie ever, Chaser of South Carolina, knew more than 1,000 words. This is double the number known by Kanzi the amazing ape, who knew about 450 words. Alex the parrot was also an impressive wordsmith, but Chaser had them all beat.

1. Halt the pregnancy for a while
   Re-absorb fetuses
2. Give birth early so the babies need less food
   Delay birth so the babies don't need to eat

In times of stress, a female rabbit's body will re-absorb fetuses to avoid giving birth to babies with no hope of surviving.

1. one
   two
2. three
   four

Cows have four stomachs because they are a "ruminant," which means they digest grass in a very long process involving some regurgitating, chewing, and burping a whole lot.

1. Two
   Three
2. Seven
   12

Russian scientist Dmitri K. Belyaev tried this out and found that if you only breed the 20 percent of the most docile foxes, in only seven generations, you get a dog-like fox that plays with you and wags its tail

1. Sperm whale
   Dolphin
2. Pufferfish
   Seal

It's true! Sperm whales have accents and regional dialects. Different pods sound a little different, and if they enter a new pod, they will pick up that pod's "idiom" and way of "speaking."

1. Banana slug
   Barnacle
2. Human
   Argentine lake duck

Barnacles may not look very sexy, but they have genitalia​ that is up to 50 (yes, fifty) times their body length. No wonder there are so many of them.

1. Snail
   Duck
2. Cow
   Penguin

Snails can sometimes don't really have a gender, or be either gender, or switch genders, so technically, they are not homosexual. However, ducks, penguins, and cows have all been seen to enjoy homosexual behavior, which puts them on a very long list of species where this has been documented - including lions, macaques, grey whales, buffalos, zebras, tamarins, and of course humans... among many more!

1. Pangolin
   Dolphin
2. Argali
   Octopus

An octopus is not a vertebrate so it cannot be a mammal. It also lays eggs and is not warm-blooded, which further excludes it.