I like sea dwelling animals that look like "glass blobjects!" This particular creature looks like a brain with "sad eyes" and a spinal column has been installed within a jellyfish.
Found originally at NotCot.org, zmescience.com has the rundown:
"...Turritopsis nutricula is a hydrozoan, and it’s considered by scientists to be the only animal that cheated death. ...
Still, our Turritopsis nutricula (could we call it Joe??) managed to find a way to beat that. What these little folks do is they revert completely to a sexually immature, colonial stage after they reach sexual maturity. They’re even cooler than that. When they’re young they’ve got only several tentacles, but at a mature stage, they get to 80-90 of them. ..."