Crab and lobster porn isn't really a thing, while Octopoda have a significant, lasting and ancient presence in Japanese lore, James Bond movies and whatnot.
The James Bond character was actually named after a real octopus that Ian Flemming met in Jamaica[1]. Flemming wanted to befriend it, but before he could, it was eaten by his housemaid. (Credit for this knowledge to the No Such Thing as a Fish podcast.)
Crab and lobster porn isn't really a thing, while Octopoda have a significant, lasting and ancient presence in Japanese lore, James Bond movies and whatnot.