The jellyfish that never dies (bbcearth.com)

I mean, the macro-organism does, in fact, die. It's an unusual way of recycling biological matter, but not a ticket to immortality. It would be akin to if we humans started budding fetal organisms when we died, which would then split off as the rest of us rotted away.

Another interesting fact about jellyfish is that they are brainless and mindless.