When marine biologist Roger Hanlon captured the first scene in this video he started screaming. (If you need to see it again, here's the raw footage.) Hanlon, senior scientist at the Marine Biological Laboratory in Woods Hole, studies camouflage in cephalopods--squid, cuttlefish and octopus. They are masters of optical illusion. These are some of Hanlon's top video picks of sea creatures going in and out of hiding.
Truth be told, I rarely link to National Geographic made-for-tv videos because narrators that sound like this are one of my major pet peeves. However, this unusual locomotion video is just too fascinating to not share. Behold how a boneless, 600lb octopus can fit through such tiny passageways. Another example here (swf/google video).