I can't quite tell what's wrong with this question. It's subtle. Maybe a second-language issue? Or maybe - just maybe - we've got an octopus out there masquerading as a human!
Fuck you, ya dirty octopus!
I'm not sure which angle is the correct one. Are we talking a human with octopus traits and/or parts, or is it the other way around?
Like, is it a human with oily poops, or an octopus with a taste for genocide?
Is it a human that can squeeze through a small hole (as long as his beak fits through), or an octopus with a favorite Baskin Robbins flavor?
Is it a human with four extra limbs, or an octopus who lost half of his in a terrible watermine accident?
I guess a human octopus would be incredible at killing, whereas an octopus human would be better at drowning.
That pretty much sums it up.
Short Answer: Anime would be very popular in either scenario.