If you want to talk about creepy and mysterious parts of the seas, than you can not exclude octopus. These cephalopods were an inspiration for monsters through the history, and their incredible possibilities are just some of the reasons. This video was recorded by some divers who managed to catch an amazing footage, and this is not something that you will see every day.
It shows just how intelligent these creatures are. You may think that you are seeing an ordinary clam, but when you take a closer look, there would be a surprise waiting for you. Veined octopuses have unique fort-building skills, and often they will collect crustacean shells and other objects to construct fortresses, or “gardens”. On the other hand some octopuses carry shells for protection.