Immortality is a Possibility

An unusual species, Turritopsis dohrnii, formerly classified as T. nutricula might be effectively immortal because of its ability under certain circumstances to transform from medusa back to the polyp stage, thereby escaping the death that typically awaits medusae post-reproduction if they have not otherwise been eaten by some other ocean organism. So far this reversal has been observed only in the laboratory. At least one professor at the Seto Marine Biological Laboratory at Kyoto University in Japan has concluded that there are three species of jellyfish that are immortal, and says their immortality may hold the key to immortality for human beings, as he says that genetically they are not that much different from humans.
https://en.m.wikipedia.org/wiki/Turritopsis_dohrnii

Dream on... Do you even know the chemistry behind Jolly fish immortality?