Octopus/ˈɑːktəpʊs/ Definition 1 of 2Pro Tip 1/3Marine Life Remember 'octopus' refers to a sea creature, distinguishable among marine life. The aquarium's octopus exhibit shows different species. Pro Tip 2/3Eight Tentacles An octopus has eight tentacles, which are key features to describe it. Each octopus tentacle has suction cups for grasping. Pro Tip 3/3Ink Escape Mention an octopus squirting ink as a defense mechanism. The scared octopus inked the water to hide from the diver.