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7 Immortal Animals That Can Basically Live Forever

Updated on May 21, 2025

These lucky creatures seem to have found the fountain of youth

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Animals that live (seemingly) forever

The Fountain of Youth remains the stuff of legends for humans, but some incredible animals have seemingly found it. These creatures were here long before us, and they have the unique ability to continue living long after us. From a whale that lived to see its 211th birthday to radiation-resistant bacteria to worms boasting limitless regeneration abilities, here are seven natural wonders that scientists say have come the closest to achieving immortality. Read on to discover these amazing immortal animals.

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Immortal Jellyfish Isolated
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Backward-aging jellyfish

At the top of our immortal animals list is a tiny variety of jellyfish known as Turritopsis doohmii, or more commonly, the immortal jellyfish. It has found a way to cheat death by actually reversing its aging process, according to National Geographic. If the jellyfish is injured or sick, it returns to its polyp stage over a three-day period, transforming its cells into a younger state that will eventually grow into adulthood all over again.

Colourful Tropical Rock lobster under water,
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Ever-growing lobsters

There is a debate among the scientific community as to whether these red ocean dwellers are biologically immortal animals. A common cause of death for them is disease, not old age, and they can grow and reproduce until they die—though not with the same mate, unlike these lifelong monogamous animals. One lobster captured off the coast of Newfoundland was estimated to be 140 years old, but most males survive into their early 30s while females live an average of 54 years, according to the Smithsonian. Fun fact: The bigger the lobster, the older it is.

Swimming Turtle with Beautiful Shell
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Sturdy turtles

Slow and steady really does win the race. Turtles have been known to live for centuries, and researchers have found that their organs don’t seem to break down over time. New York Times reports that turtles might even be able to live indefinitely if they are smart and savvy enough to avoid predators and disease. In other words, they definitely have the potential to be immortal animals.

Pseudoceros concinnus Flatworm
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Regenerating flatworms

These creepy crawlers, also known as planarian worms, are famous for their regeneration abilities, where a worm cut across or lengthwise can form two separate worms. This apparently limitless regeneration also applies to aging and damaged tissue, allowing the worms to cheat death indefinitely, according to a study at the University of Nottingham.

Humpback Whale and Baby
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Toughest whales

Though not technically an immortal animal, the bowhead whale is the oldest living mammal. According to Popular Science, several species of whales have been known to live for more than 70 years, though in the 1990s, scientists discovered scars on the massive beasts (among the biggest living animals in the world) that had been made by weapons from the 1800s. The oldest known bowhead lived to be 211 years old.

Radiation-resistant bacterium

Deinococcus radiodurans, a poly-extremophilic bacterium, isn’t only radiation-resistant. These immortal animals can also die and come back to life thanks to their incredible DNA repair response. According to Ira S. Pastor, CEO of Bioquark Inc., “[They] can survive cold, dehydration, vacuum and acid, and [have] been listed as the world’s toughest bacterium.” The Guinness Book of Records even says they “can resist 1.5 million rads of gamma radiation, about 3,000 times the amount that would kill a human!”

Tardigrade (Water Bear). 3d rendered illustration.

The most indestructible species on the planet

Anything that tries to kill a tardigrade will quickly realize they encountered a practically immortal animal. These are creatures capable of sticking around for thousands of years, or even indefinitely, “by entering a state of cryptobiosis, whereby their metabolism comes to a halt,” says Pastor.

Additional reporting by Chelsea Stone.

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