This group of creatures includes squid, octopi, and cuttlefish. They are frighteningly intelligent for creatures with no backbone. Also frightening: the swivel-hook-studded tentacles of a colossal squid.
To those who say that sea monsters do not exist: I beg to differ. Imagine, if you will, a squid 40 feet long, with tentacles that not only have tiny teeth ringing the suckers, they have swiveling hooks. Apparently scientists deduced the existence of the colossal squid based on finding squid beaks in the stomachs of sperm whales– whales which also had some serious battle scars from altercations with said squid. What I want to know is, how many of the whales lost? We may never know. I’m kind of hoping to find out that somewhere out there is a supercolossalgigantosquid that has survived for thousands of years precisely because it was smart enough not to be discovered by humans.
Apart from growing to Vernean sizes, cephalopods also do cool things like carry coconuts with them to hide in and shoot out of the water using their jet propulsion systems. They can also escape from holding tanks, disguise themselves as other sea creatures, release a cloud of obscuring ink to facilitate escape, communicate in code, and defuse a bomb while driving an Aston Martin.
Tabitha's Island 