5 Terrifying Animals That Could Save Your Life Someday

5 Crocodile Blood Might Kill Deadly MRSA Bacteria ... and HIV

Have you ever seen a crocodile apply antibiotics to his wounds after a gang fight? No, probably not, because their arms are so short. But you also never see crocodiles die of infection despite suffering horrific gashes while living in a bacterial soup of swamp water. After a major battle, crocs walk/swim away, heal up and go about their usual routine of pretending to be logs and floating in filth. This is why scientists started studying crocodile immune systems -- we've got people losing limbs to bacteria up here in the people world, so why aren't crocodiles dying of infection while living in an ecosystem experts refer to as "nature's toilet"?

So scientists grabbed some crocodile blood and started exposing it to different infections, including HIV (if you've ever met a crocodile with AIDS, that's some sad shit). What the researchers found was that while human blood could kill eight of the 23 strains of bacteria they attacked it with, alligator blood killed all 23, including antibiotic-resistant MRSA. From that point forward, the scientists renamed croc blood Muhammad Ali and human blood Screech Powers.

It turns out the crocodile's whole immune system is organized differently from ours. Instead of getting too technical about how it works, we'll let Australian scientist Adam Britton explain it: "The crocodile has an immune system which attaches to bacteria and tears it apart and it explodes." Fuck yes.

So it is hoped that the croc blood proteins can be developed into drugs for humans (drugs that we hope will have pictures of crocodiles on the label), since those tests revealed that crocodile serum could explode lots of bacteria that plague humans, even those superbugs that are resistant to penicillin.

And yes, later tests showed it was also effective at killing HIV. There is a lot more testing to be done, so don't go crazy yet. It will take years just to make sure pumping a sick person full of crocodile blood doesn't turn them into Killer Croc.

4 Cobra Venom Might Stop HIV and MS

The greatest movie villains of all time weren't messing around when they named themselves after the cobra and the kai. Cobras are the devil. Did you know they spit venom at your eyes, the second worst place you can get snake venom? If you get enough of it in your system, get ready to enjoy pain, necrosis and maybe even paralysis, as the toxins bind themselves to neuromuscular junctions, blocking communication between the central nervous system and your muscles. Because mercy is for the weak, and an enemy deserves no mercy.

So how in the hell could that ever make a person's life better in any way?

Well, scientists think that part of what makes venom so nasty is that it suppresses the body's ability to fight back by hampering the immune system's normal healing process. So if you had a disease caused by an overactive immune system, a chemical that slows it down would be the proverbial vigilante crime fighter keeping a corrupt police department in check. This may be why in India cobra venom is considered an arthritis cure -- arthritis is caused by the body's own immune system keeping the sufferer's joints chronically inflamed.

So then you start looking at other even more horrible diseases, like multiple sclerosis and HIV -- both of which involve royal cock-ups in the immune system. Although science is still not sure of what causes multiple sclerosis, we know that for some reason the immune system begins to destroy the protective layer around the body's neurons, which sucks because neurons are the metaphorical heart of the nervous system. It's kind of like shooting through your own shields in Space Invaders. Only instead of dropping your head in shame and running out of the arcade because it's 1982 and you're in an arcade for some reason, you end up with scars that keep your brain from communicating with the rest of the nervous system.

In theory, snake venom could keep that self-destructive process in check, if only it wasn't, you know, incredibly toxic (because it's snake venom). Fortunately, a company has patented a process for removing the paralyzing part of the venom, and what's left acts as a kind of regulator to the immune system's Wild West anarchy, halting the development of MS in 90 percent of the rats treated for rat MS.

Oh, and we need to talk about HIV for the second entry in a row, because research shows that cobrotoxin (the stuff in cobra venom, if you couldn't figure that out from the name) also might stop HIV. The way the venom goes to work on the immune system kind of shoulders HIV out of the way (they latch onto the same receptors in the cells). So here's to a future where after a positive HIV test, the doctors immediately start pumping you full of snake venom and crocodile blood.

3 Vampire Bat Spit Can Save Your Brain

If you have a vampire bat flapping around your head right now and you're getting scared because, you know, it's called a vampire bat, we have good news: Vampire bats don't actually suck your blood.

Instead, it'll just bite you and then leisurely lick the wound as blood leaks out, like you're his lollipop. After he's had enough, he'll fly off and leave you to keep bleeding for several hours.

Yes, hours. This might seem weird to you as you watch it soak through one Band-Aid after another, since we're talking about a tiny wound made with little baby bat teeth. Shouldn't that little nibble scab over after, say, an hour? No, because vampire bat spit contains a blood thinner that keeps the blood flowing in case he or his friends want to come back for another drink from the red fountain. They really thought of everything.

So how does this help you, or anyone else other than gauze manufacturers? Well, imagine you're having a heart attack in your brain, otherwise known as a stroke. Blood flow to your brain has stopped, usually because of a clot blocking up the blood vessel. So your brain has a freakout because it's not getting oxygen, and depending on which part of the brain was damaged, your body has its own meltdown. If you get to a hospital, the doctors can administer a medicine to break up the clot as fast as possible, but only if it's been no longer than three hours since the symptoms started.

At that point, there's still a chance they can dissolve the clot and protect the brain from further damage, but the medicine also has a 1-in-15 chance of causing bleeding to the brain, so maybe they save your motor functions but flood your brain with blood and kill you. If you had a stroke right before bed and didn't figure out anything was wrong until you woke up, you're shit out of luck, because no one is going to administer the clot-breaking medicine.

That's where bat spittle comes in. Early tests have found that there's a protein in bat spit that can bust clots for up to nine hours after the onset of a stroke. Nine hours is huge in stroke-time; it could mean the difference between living the rest of your life as a vegetable and living your life with a slight slur that adds interest to your character, depending on where the damage was done. And the drug might be available to doctors as soon as 2014.

2 Shark Skin Bacteria Repellent

Between Jaws, Shark Week and the blood-curdling choreography from the Latino gang in West Side Story, most of us have gained a healthy appreciation of sharks. Sure, we know that more people are killed by cows than by sharks every year, but you can't look at those soulless beady eyes and that mouth full of gum razors and not shiver until the pee comes down.

Maybe it's our irrational fear of the scapegoats of the sea that kept us from noticing something important about them: Nothing sticks to their skin. While whales are dripping in barnacles and manatees collect enough algae to host garden parties on their backs, sharks stay smooth. And it's not just because the bacteria is scared.

It turns out that a shark's skin has special denticles to repel everything from it. That's because their skin isn't skin skin, it's scales. You just thought they had smooth skin because the scales are so freaking awesome in how they work. Rub their skin one way, and the scales are as smooth as a baby's butt. Rub it the other way, and the scales are as rough as a full-grown man's butt. That's because the scales are arranged in a diamond pattern that creates an air cushion when you rub them toward the tail, but go rough when you rub them toward the head. And what scientists figured out is that algae and bacteria don't like to live on shark skin, because its unique texture makes it hard for the tiny organisms to attach themselves to it.

It only took a little research to figure out how to duplicate the pattern that made shark skin bacteria-repellent. So the first thing scientists did with this technology was cover Navy ships and subs in a plastic sharkskin film that also repelled algae. The second thing they did was make Michael Phelps a special suit so he could win medals. The third thing they did was say, "Holy shit! This could also save millions of lives!"

Up until now, in the war against deadly bacteria, we've usually employed one tactic: kill it. Kill every bug we can with antibacterial soap, medicine and tiny knives. And in response, the bacteria has just gotten resistant, thanks to the miracle of natural selection. Which is why 99,000 Americans a year die from infections they got in the hospital. But if we could make surfaces the bacteria simply don't like to grow on ...

That's why a company called Sharklet Technologies is now marketing a sticky film covered in the sharkskin pattern to use on all of the hospital surfaces that collect diseases -- the bedside tables, door handles, even those plastic bracelets no one ever thinks to disinfect. So the next time you're swimming in the ocean and a shark bites off your arm, give him a little wink of thanks. His skin might keep you from losing the rest of your body to infection.

1 The Pit Viper Has Probably Already Saved Someone You Know

The jararaca snake is a pit viper who really doesn't deserve a name as fun to say as "jararaca." Its bite can do a whole host of shitty things, including something called compartment syndrome. Sounds harmless, right? Well, compartment syndrome squeezes muscle tissue into a dense space until the skin suffocates and dies. And it looks like this: WARNING: CLICKING THIS WILL SHOW YOU A MAN'S LEG WITH THE SKIN SPLIT OPEN, SHOWING A BASEBALL-SIZED CHUNK OF EXPOSED MUSCLE TISSUE.

That actually has nothing to do with this entry. We just wanted you to know how serious the pit viper is. For the most part, the jararaca bite works a number on your blood, causing your blood vessels to dilate and your insides to hemorrhage. But before all that takes place, the victim collapses in a heap because of a sudden drop in blood pressure. And in the 1960s, researchers figured out why: The venom contains a protein that blocks angiotensin-converting enzyme, or ACE. That's the enzyme that keeps your blood pressure at the right level. Block it and your blood pressure falls; block it enough and you die.

At this point, you can already guess where this is going: High blood pressure is an indicator of a future stroke, heart disease, aneurysms, death and a medicine cabinet full of pills. Oh, and 31 percent of Americans over age 20 have it. So high blood pressure kills way more people a year than pit vipers, is what we're saying. But what if we could use the pressure-dropping power of jararaca snake venom to help people who can't stop eating potato chips? In 1975, that's exactly what the pharmaceutical company Bristol-Myers Squibb did. By the early '80s, yuppies everywhere had access to a drug that would reduce the blood pressure that came from playing the stock market game and constant cocaine use, with its most common side effect being a cough.

Not bad for a poison that can turn your leg into a giant vagina, huh?

And for animals that are just going to straight kill your ass, check out The 6 Cutest Animals That Can Still Destroy You and The 6 Deadliest Animals Too Adorable to Run Away From.