Slow and steady really does win the race. Turtles have been known to live for centuries, and researches have found that their organs don’t seem to break down over time. The New York Times reports that turtles might even be able to live indefinitely if they are able to avoid predators and disease. In other words, they definitely have a potential to be immortal animals. (Don’t miss the 8 smartest animals that learn faster than humans.)
Regenerating flatwormsTom Wellenmann via Flickr
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.
Though not technically immortal animals, 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 animals that had been made by weapons from the 1800s. The oldest known bowhead lived to be 211 years old. (Whales are also very smart. This particular one even thanked the scientists who rescued him from a fishing net.)