Toothy Grins

Teeth are vitally important tools for every species that has them, but in the mouths of some animals, teeth are downright terrifying. They can be a couple of feet long and razor sharp. And the bigger they are, the faster you'll run.
Alligator

Fun fact: Alligators possess the second strongest bite on Earth (after their crocodile cousins) and are faced with no predators of their own.
Shark

Fun Fact: As if they weren't terrifying enough on their own, sharks can have up to 3,000 teeth at one time. These predators make use of their vicious bite to grab and kill their food. They gnaw on whatever they catch and rip it into bite-size chunks. Fun visual, right? Sharks are also constantly losing their teeth. They replace them in a conveyor belt-like manner, with teeth shifting forward in their mouth as other ones fall out.
Polar Bear

Fun Fact: Polar bears have about 42 teeth in their mouth, and their bite is twice as strong as a brown bear's. Unsurprisingly, polar bears use their massive teeth to hunt and eat their prey. Their incisors shear off pieces of blubber and their canine teeth tear hides. They swallow their food in large chunks once their teeth have done their job.
Lion

Fun fact: A lion's jaws are essential for taking down prey. When a lion attacks a wildebeest or buffalo, it clamps its jaws down on its victim's throat, crushing the trachea. Once the prey is dead from suffocation, the pride feasts.
Baboon

Fun fact: Baboons aren't natural carnivores, so those huge teeth don't help the apes hunt and eat meat, as you might have suspected. That doesn't mean they're not dangerous, though. Baboon males use their teeth to fight each other in vicious competition for baboon females.
Elephant

Unfun fact: For hundreds of years, elephants have been hunted and killed for their tusks, which are enlarged incisor teeth made of ivory. The practice continues today. Despite a dip in elephant poaching due to international efforts in the early 1990s, the barbaric practice has experienced an alarming surge in recent years.
Jaguar

Fun Fact: Jaguars pack a mighty punch with their bite. Most large cat species grab their prey by the throat and suffocate it. Jaguars use a different approach. They pierce the prey's skull or neck with one bite, immediately killing it with the impact of their bite. It's believed that their ferocious bite can be twice as strong as a lion's!
Camel

Fun Fact: Our favorite visual reminder of "Hump Day" has a mouth full of all sorts of teeth, some of which can grow up to three inches long. It seems pretty unnecessary for a herbivore species to have such strong teeth, but they put them to use. Dromedary camels, aka "one-hump camels," are known to have a vicious bite when provoked. Steer clear of a camel's mouth, if you ever have the occasion to meet one.
Hippopotamus

Fun fact: Hippo teeth can reach nearly 2 feet in length, backed by the most powerful bite of any land mammal. And despite their meatless diet, it takes little provocation for hippos to attack humans. Hippos kill more people in Africa than any other animal.
Walrus

Fun fact: Both male and female walruses possess large canine tusks, and they use them in a variety of ways. Their tusks serve as tools for breaking ice or as weapons used in territorial and mating competition. Walruses even use their tusks to haul themselves out of the water.
Babirusa

Fun fact: Male babirusas' canine tusks grow continuously throughout their entire lives, curling backward toward their faces. If they don't grind down their tusks, they would grow to the point of penetrating the animal's skull.
Warthog

Fun fact: The warthog's tusks are unusual in the way the upper tusks protrude from the snout to form a semicircle. The shorter lower tusks rub against the upper tusks every time the warthog opens and closes its mouth. This makes the lower tusks razor sharp.
Sheepshead Fish

Fun fact: In fish, any teeth at all are "huge teeth." The deeply unsettling sheepshead not only has teeth that look remarkably like a human's, but it also has rows and rows of them. These fish possess distinct incisors and molars, which allow them to consume a diverse, omnivorous diet.
Hyena

Fun Fact: The scavenger species is known for their maniacal laugh, but what's perhaps more disturbing is their teeth. Hyenas have massive jaws and very strong teeth, both of which they put to good use. They are able to grind bone, teeth, horns and hooves into a digestible substance. Hyenas eat every part of a carcass in front of them, putting new meaning behind "cleaning your plate."
Musk Deer

Fun fact: Have you ever seen a saber-toothed deer before? Musk deer are the only members of the taxonomic family Moschidae. Unlike true deer, musk deer do not grow antlers. But they make up for that with those cool, freaky canine tusks.