“The mystery of life is not concealed in the higher animals. It is concealed in the root. And at the root of the Tree of Life is the jellyfish.”
In an interesting, and then bizarre and lovely, long-read for the New York Times Magazine, Nathaniel Rich considers the immortal jellyfish (not pictured) and the people who study it, including Dr. Shin Kubota, a.k.a. Mr. Immortal Jellyfish Man, quoted above.
The story also vaguely suggests that the immortal jellyfish is what remains of someone or something that traded its soul to the devil. Related: Deals With the Devil in Popular Culture.