The "immortal jellyfish" is the most amazing thing I've learned about in a while. “When this jellyfish gets old or gets hurt, instead of just dying... it transforms itself back into a baby jellyfish and grows up all over again. It can do this as many times as it wants, which means theoretically it never has to die from getting old, it just keeps hitting the reset button on its life.” https://www.theguardian.com/environment/2026/aug/04/when-you-kill-it-it-doesnt-die-the-jellyfish-that-has-cracked-the-secret-of-immortality