Horrible, really.
There are octopuses out there with more than 8 arms. In fact, they have a specimen with 96 tentacles

96!
This monstrosity even reproduced, though I am relieved to report that all of her fiendish spawn not only died, they had the normal amount of legs.
But imagine, just imagine, that horrible, sticking, wet sensation as an octopus grabs onto your leg to drag you to the inky depths. Now imagine it times 12! There would be no escape. No time to scream, to call for help or even to send one last, hard telepathic thought of love and warmth to your dear ones.
There would only be the hideous grapple. Then cold death on the bottom of the ocean. She would suck out your eyes and each tentacle would grow stronger and she would wait for her next victim.
Nature is a cruel beast.