Benjamin Button Jellyfish

As called immortal jellyfish species, the Benjamin Button of the deep, which can age backward and silently fall into the world's oceans, swarm by swarm. This jellyfish can transform from an adult into a baby, but unlike Benjamin Button, the jellyfish can do it repeatedly. In the Mediterranean Sea, this immortal jellyfish (Turritopsis dohrnii) was discovered in 1883. Its unique ability was discovered in the 1990s. It regularly reverts into a sexually immature stage after reproduction and when injured or starved. The only way it can die is to be eaten, removed from the water, or infected.