12. Immortal Jellyfish: Resetting the Clock
The immortal jellyfish (Turritopsis dohrnii) has one of the most astonishing adaptations in the animal kingdom. When faced with stress or injury, it can revert its mature cells back to their earliest form, essentially starting life over again. This biological reset gives the jellyfish the potential for endless cycles of youth and old age, making it a subject of intense anti-aging research. More info here.