Eddie_Shack
likes oatmeal lumpy
It may not live in the deepest depths (though it does live pretty deep), but there is a jellyfish that can return at any point to its polyp stage. That would be the equivalent of us returning to a prepubescent state. The transition, though, makes the jellyfish essentially immortal since it can literally reset its lifespan. If it doesn't get eaten or stricken with disease, it will literally live forever.
How cool is that?
You just blew my mind.