It can be a scary world out there. From 1,000-pound man-eating crocodiles to tiny parasite-carrying insects, humans face many threats in the natural world. Some are the kind of dramatic killers that make the evening news, like shark attacks or the occasional bear mauling.

But just as often it’s an attack at the hands (or fangs or stinger) of a creature that we wouldn’t have imagined could bring sickness and death. Find out more!

Golden Poison Dart Frog

These brightly colored frogs are as beautiful as they are deadly. An inhabitant of the northern part of South America and measuring a mere two inches when fully grown, just one of these frogs packs enough poison (called batrachotoxin) to kill 10 grown men.

Unlike venomous snakes or spiders, these creatures don’t need to bite to kill; simply handling them can transfer poison to a person.

Box Jellyfish

This many-tentacled killer floats off the coast of northern Australia and adjacent seas, and is easy for swimmers and surfers to miss as they head out into deep waters.

The National Oceanic and Atmospheric Administration considers it the most venomous marine animal in the world, striking with thousands of stinging cells, known as nematocysts, that strike the victim’s heart, nervous system, and skin cells all at once.

Blowfish

Also known as a pufferfish, these creatures have two impressive defense options: When threatened, they “inflate” their elastic stomachs with water, making them hard for a predator to get its jaws around them.

But more devastating is the tetrodotoxin it carries, a poison that not only makes it taste terrible, but is deadly to those fish or humans who make the mistake of trying to eat it.

Indian Cobra

Native to Pakistan, Sri Lanka, and, as per its namesake, India, these hooded creatures are immediately recognizable and can grow to five to six feet long. Their bites cause severe pain, swelling, and paralysis, with death occurring in as little as 15 minutes for those left untreated.

Cone Snail

Another killer in the “looks beautiful and harmless, is actually super deadly” category, these brown-and-white snails that live in the warm Caribbean and Hawaiian waters hide a set of harpoon-like “teeth” (actually called “radulae”) packed with conotoxin, which wrecks its prey’s nervous system, paralyzing it before it devours it.

Deathstalker

This scorpion is so lethal, it even has “death” in its name. Its highly toxic venom is matched by its incredibly fast lunge, which allows its poisoned stinger to whip over its head at 130 centimeters per second, striking its prey before it even knows what hit it.