Interesting Fact
There is a species of jellyfish, Turritopsis dohrnii, which is theoretically immortal. It can revert from its adult jellyfish form, to its juvenile polyp form, and back an unlimited number of times without aging.
https://en.wikipedia.org/wiki/Turritopsis_dohrnii
https://en.wikipedia.org/wiki/Turritopsis_dohrnii
