Three traits of the octopus package them with the ability to inhabit different marine habitats, taking down preys such as crustaceans and mollusks. Despite these, they have their natural enemies, too. They are vulnerable to the attack of cetaceans, sharks, pinnipeds, sea otters, or sea birds. However, another phenomenal attack of the giant octopus takes down a shark, which leads us to think that size matters when it comes to the attack. We cannot really say about the outcome since things can change in the blink of the eye. Shrimps, crabs, and lobsters belong to the category of the crustaceans. Cetaceans, on the other hand, refer to whales, dolphins, and porpoises. The defense mechanisms have allowed animals to have a high successful survival rate. Octopuses, with the ability to spill ink, is one of the examples, although this will not always work. Aside from the ink cloud, the venom and coloration are also the defense mechanism. Blue-ringed octopuses are the representative, and their toxicity can kill you in a minute.