thanks for those links, we're thinking along the same lines, as one of the other models i've been slowly working on for this project is an alien jellyfish.
here's a very early animation test of it's body and tentacles, but without it's dome. also the animation is quite robotic (stiff looking) so i need to do a lot more work on that:[link]
the objects in the latest videos here on da, weren't originally intended to look, or behave, like creatures, although over the time i've been developing them i've realized they could be.
saying that, the concept for this one was that the large globule type object is being suspended by thick strands (as opposed to actual tentacles with tips to them) with the ends of the strands attached to the background (environment) object, seen here in a recent test:[link]
and eventually i intend the smaller jellyfish to be swimming/flying around the other objects.