A lot of things are “immortal,” like Einstein or Elvis who have been immortalized with something they were known for. But today, we got ourselves a really real immortal fella. What is known as the immortal jellyfish, turritopsis dohrnii, is biologically immortal.
So what it does is that once it reaches the end of its lifetime, the jellyfish reverts back to its polyp state. That means that it goes back to its first stage of life, so that it can grow back into an adult again. So long as the little jelly isn’t eaten, it lives forever. Oh yeah, lobsters aren’t immortal if you guys saw that rumor laying around anywhere.