(Mental Floss) -- Sure, you know these five creatures as stinging, biting merchants of death. But isn't it time we put aside our differences and embraced the positive?



A creepy crawler from this guy's family could save your brain from cancer some day.



1. Poison dart frogs: The heart-healthy choice



It could kill you: You know an animal is bad news when its sweat was once considered a state-of-the-art military technology. Meet the poison dart frog, which secretes a highly dangerous neurotoxin, called batrachotoxin, through its pores.



In fact, various Latin American tribes used to collect the stuff (carefully) to poison the tips of their arrows for hunting and warfare. Interestingly, however, the frogs don't produce their own toxin. They get it from eating insects that most likely pick up the poison from the plants they consume. The same frogs, if raised in a laboratory rather than the rain forest, aren't poisonous at all.



But it just might cure you: Before batrachotoxin stops your heart, it speeds it up. Consequently, medical experts believe it might be possible to tweak elements of the frog's toxin to bring patients out of cardiac arrest and potentially save lives. And because it also deadens nerve endings, batrachotoxin has potential as an ingredient in anesthetics.  Watch how gator blood may be become super drug »



Studies into other uses of the toxin are still in the early stages, but the frog's medical benefits bolster the argument for preserving the rainforest. Most scientists believe we've only just begun to grasp the pharmaceutical possibilities of some of the world's rarest and deadliest creatures.



2. Scorpions: Leading the battle against brain cancer



It could kill you: For the most part, scorpions use their toxins to capture prey, ward off competitors during mating season, and defend themselves against larger predators. Unfortunately, humans count as larger predators. A sting by some species can leave you with any number of potentially deadly conditions, including heart and lung failure.



But it just might cure you: Medical researchers at the University of Alabama at Birmingham (UAB) have discovered a new use for scorpion venom -- cancer medication. Each year, some 9,000 Americans are diagnosed with malignant glioma, a form of brain cancer that kills about half its victims within a year of diagnosis.



Glioma cells work a lot like cockroach muscle cells. And while that fact is pretty disgusting, it also got UAB researchers thinking about the giant Israeli scorpion, whose venom is harmless to humans but deadly to its cockroach prey.



Doctors found that when they injected a drug derived from the venom of giant Israeli scorpions into cancer-infected human brains, the poison destroyed the glioma cells and left surrounding, healthy cells alone. The treatment is still in the early stages of development, but researchers remain optimistic.



3. Cone shell snails: Little creatures tackling big pain



It could kill you: Thanks to their unique colors and intricate patterns, cone shells look like they'd make great beach souvenirs. But watch your fingers; they're actually home to one of the world's deadliest creatures. Cone shell snails come equipped with an extendable "arm" -- complete with a sharp, venomous tooth -- that they use to immobilize and kill prey.



And while the venom certainly helps the slow-moving hunters from going hungry, it can also paralyze, or even kill, victims. The good news: Death by cone shell is completely painless.



But it just might cure you: Cone shell venom, called conotoxin, has incredible potential as a painkiller, with one added bonus: Unlike many current anesthetics, conotoxin isn't addictive.



In 2005, Ireland-based Elan Pharmaceuticals became the first company to market a drug made from the venom. Called Prialt, the drug is pumped into the fluid around a patient's spine to relieve chronic pain and is believed to be up to 1,000 times more powerful than morphine.



Meanwhile, at the University of Melbourne, a research team headed by Professor Bruce Livett is currently developing another conotoxin-based painkiller called
What deadly creature can help brain cancer patients? What do scientists hope can save humans?
Scorpions: A creepy crawler
question: What deadly creature can help brain cancer patients?, answer: Scorpions: | question: What do scientists hope can save humans?, answer: A creepy crawler