The immortal jellyfish (Turritopsis dohrnii) is a hydrozoan jellyfish that can revert back into an immature polyp, and then mature into a jellyfish again. In the original paper describing the species, the scientists wrote that, in reverting back to youth, the species was capable of “thus escaping death and achieving potential immortality.”
Learn more about the current science of the organism in this week’s New York Times Magazine feature.
Edit: The NYTimes article may not be very scientifically accurate! Read science media critic Paul Raeburn’s critique on the Knight Journalism Tracker.