Octopus escaping through one inch hole. Octopus eats shark. Camouflaged octopus. Octopus attacks mini-sub. (Google videos)
A giant octopus takes on a shark in a video like something from a horror movie (low-res version). Octopuses are remarkable creatures, and are much more intelligent than you may think, especially given some of the movies they've inspired.
Camouflaged and Walking octopuses Octopus marginatus and Octopus (Abdopus) aculeatus, that walk along the seafloor using two alternating arms and apparently use the remaining six arms for camouflage.
Did he who made the lamb make thee? O. vulgaris, now appearing on a sea floor near you.