No kidding! Really? Wow! What a revelation! 🙄 This is why it wouldn’t be just a plain old octopus. It would be something like one, only NOT one. Amazing what you can do in fantasy land.
This wouldn’t be another lame spider, and it would be vastly different from squid. It should be a night spawn that spits venomous ink. It should make a strange underwater crackling noise and when defeated is should drop eight bones and a single ink sac with ink that is only visible to the author of the book.