The octopus is one of the most intelligent sea creatures. They have special characteristics to defend themselves such as camouflaging, emitting lights to distract and disorient predators, expelling of ink, fleeing thru jet propulsion, and mimicking other animal body structures.
They are also known to collect tools such as shells and trinkets to create a temporary home for themselves. In fact, it has been observed that an octopus grab and carry coconut shells around for them to use as a shelter and protective barrier against big predators. ( whalefacts.org )
photo/video source: Earth Touch| Youtube