I have eaten chopped up living (yes, it’s still alive) octopus and it tastes like whatever sauce you dipped the squirming little pieces of leg into. Rubbery. And you MUST chew well enough that one of the suction cups won’t grab your throat on the way down; as someone said people have died choking on even one piece they couldn’t dislodge. Of course, such death is rare and most who choke manage to chuck it out somehow.
Eating a whole octopus is a whole ‘nuther experience. I’ve never done it and will never try because it can be seriously dangerous if you don’t chew, chew, chew, and be absolutely sure you’ve crushed every single suction cup — because if even one of them survives your teeth…well, I don’t know. Anyway, I saw videos of people eating a whole one, so I know some fools do it, and once on one those challenge TV shows where famous personalities are tapped for some fun in quirky ways. Only the juveniles of the species that live in the tidal flats (not the large rock octopus) are eaten eaten live, don’t mention eaten whole. They put chopsticks up into the head, twirl them around and around until the tentacles are wrapped, dip it in some red pepper sauce, usually quite spicy, shove it into the mouth, and chew, chew, chew while everybody laughs. HA HA HA. Not.
I no longer eat raw shellfish or mollusc of any type, as a friend died from a rare worm infection. We don’t know whether it was small clams, mussels, sea urchin, sea cucumber or octopus, as he had some of each. They invaded from his gut into his lungs and he died on the third day in hospital — otherwise healthy as a horse in his early sixties.