Picture #1 is very much dead, probably preserved in ethanol?
Picture #6 is the first photo I've seen of a person holding a cirrate octopus. Really brings home the size and the gelatinous consistency.
Picture #7 is definitely the cutest.
I know all three look very different, but gelatinous animals have a tendency to look extremely different in vs. out of water, and alive vs. preserved. So they could all be the same beast, in different states.
Picture #3, by the way, is of the otolith (ear-bone) of a rat-tail fish. This isn't clear from the caption, but ALL fish have otoliths, and ALL otoliths have growth bands that can be counted like tree rings. These features are in no way unique to rat-tails.
However, I once wrote a unique poem about rat-tails.