© Shutterstock

Immortal jellyfish -

The clue is in the name. These amazing creatures have the ability to age backward, Benjamin Button style! Basically, when they’re injured or starving, these jellyfish can revert themselves to a younger state.

© Shutterstock

Cockroaches -

There’s a good reason why roaches have a reputation for being tough. They can endure extreme temperatures, and can even survive up to 45 minutes without air.

© Shutterstock

Cockroaches -

Not to mention that they can feed on odd things such as concrete. And while a nuclear blast would probably kill them, cockroaches can actually take a lot more radiation than humans and survive (six to 15 times more).

© Shutterstock

Devil worms -

Discovered in a South African gold mine in 2011, these worms (Halicephalobus mephisto) were living at depths of 2.2 miles (3.6 km). But what’s more impressive is that they had been there between 3,000 and 12,000 years.

© Public Domain

Tardigrades -

Also known as water bears and moss piglets, these small creatures are as tough as they get. They can survive without water for up to 10 years and can live in temperatures ranging from -457°F (-272°C) to 302°F (150°C). Oh, and did we mention that they can also survive radiation?

© Shutterstock

Pompeii worms -

These creatures can be found attached to hydrothermal vents in the Pacific Ocean. As you can imagine, these are hot: 176°F (80°) to be more precise. Not to mention the plethora of toxic gases they emit. And did we mention that they are so deep in the ocean that there is no light whatsoever?

© Shutterstock

Arabian camel -

The Camelus dromedarius can go for 100 miles (16 km) without drinking and can withstand temperatures of 120°F (48°C). That's one tough animal, right?

© Shutterstock

Strain 121 -

Although not an animal as such, this single-celled organism can survive temperatures of 266°F (130°C).

© Shutterstock

Strain 121 -

Scientists put them in an autoclave used for medical sterilizations to test these microorganisms’ resistance to heat. For 10 hours! Shockingly, they survived.

© Shutterstock

GFAJ-1 -

Again, not quite an animal, but this extremophile (an organism) discovered in 2010 near Mono Lake, in California, is worth a place on this list. They can feed on things such as phosphorous and arsenic, and they gave NASA hope in finding similar tough organisms on other planets.

© Shutterstock

West African lungfish -

In addition to gills, these "living fossils" have special lung-like swim bladders, which allow them to survive, even if buried. Plus, they can remain dormant for about six years through a process known as estivation (similar to hibernation).

© Shutterstock

Red flat bark beetles -

These insects are tough. So tough that they can survive temperatures as low as -238°F (-150°C). You can find them in parts of Canada and Alaska.

© Shutterstock

Desert elephant -

Elephant populations living in Namibia and Mali are adapted to extreme conditions. They can travel around 40 miles under 122°F (50°C) heat to find water and often go without drinking for about three days.

© Shutterstock

Arctic lemming -

Unlike other mammals found on the Arctic tundra, these small rodents don't hibernate. Instead, they endure the extreme cold winters by keeping active, building tunnels under the snow where they can search for food.

© Shutterstock

Caribou -

These reindeer endemic to Northern Europe and North America can endure extreme winters. They are the only deer found north of the Arctic tree line.

© Shutterstock

Emperor penguin -

These cute animals can dive deeper than any other bird in the world. They march between 30 and 90 miles (48-144 km) to remote and extremely cold places where they form colonies. Emperor penguins can withstand wind chills of -76°F (-24°C).

© Shutterstock

Gray-crowned rosy finch -

While some of them migrate south in the winter, those of the Aleutian and Pribilof Islands in Alaska live there year-round. They also have been found to breed higher than any other bird in North America, at Mount Denali (20,310 feet or 6,190 m above sea level).

© Shutterstock

Polar bear -

Unlike other bears, the Ursus maritimus doesn't hibernate in winter. Polar bears are extremely well adapted to the cold and can survive harsh conditions thanks to their two-layer fur and other amazing features.

© Shutterstock

Himalayan jumping spider -

The Euophrys omnisuperstes has been found at heights of 22,000 feet (6,705 m) on Mount Everest. They have superb vision (four eyes!) that allows them to spot their prey and jump on them.

© Shutterstock

Common fangtooth -

This deep-sea creature has larger teeth than any other ocean fish, relative to its size. They can be found at depths of 16,000 feet (4876 m), where pressure is around 500 times higher than at sea level. Plus, it's pitch black down there!

© Shutterstock

Water-holding frog -

Southern Australia’s water-holding frogs are able to survive the hot and dry months by getting into a sort of cool hibernation mode. They bury themselves in the mud, inside a mucous cocoon, and emerge when the rainy months return.

© Shutterstock

Pacific viperfish -

These predatory fish live in the depths of the sea but swim to shallow waters at night to hunt. They have this cool, ultra-black skin that helps avoid detection while hunting, though they do use bioluminescence to mate.

© Shutterstock

Vampire squid -

These have really big eyes. In fact, vampire squid has the largest eyes of any animal relative to its body size. They live and thrive in a light and oxygen-depleted environment.

© Public Domain

Northern viper -

The Vipera berus can survive at 23°F (-5°C), and can still move around when temperatures plummet to 29°F (-1.6°C).

© Shutterstock

Frilled shark -

Considered a living fossil, these predators can be found at depths of 4,920 feet (1,499 m). These deep-sea sharks have around 300 teeth!

© Shutterstock

Giant spider crab -

The giant spider crab has a leg span of nearly 13 feet (3.9 m), making them the largest arthropod living up to 1,300 feet (396m) deep in the Pacific Ocean. Their exoskeleton is hard enough to deal with changes in pressure effectively, and they hunt on the seabed.

© Shutterstock

Siberian salamander -

This salamander is so adapted to the cold that it can freeze yet remain alive. How cool is that? Pun intended!

© Shutterstock

Namib Desert darkling beetles -

Living in the dry desert, these beetles have a unique way of collecting water from fog. They stand with their backs raised and heads lowered, collecting water droplets on their bodies, which then flow down to their mouths.

© Shutterstock

Spectacled eider -

This sea duck can be found in Alaska and northeast Russia. They survive the harsh winters congregating in flocks between ice patches on the Bering Sea. 

Sources: (Grunge) (Stacker)

See also: These animals don't mind living in splendid isolation

© Shutterstock