[setgree]

You might enjoy 'Children of Ruin' by Adrian Tchaikovsky, which explores this idea in depth with a civilization of genetically modified, super-intelligent octopuses. (Though I'd start with the first book in the series, 'Children of Time')

[zbirkenbuel]

A solid series, with descriptions of thought process feeling truly alien. I'm currently enjoying "The Mountain in the Sea" by Ray Nayler for more octopus based speculative fiction

[abhgh]

I would also recommend "The Mountain in the Sea"! I have mentioned this earlier on hn that I like it because it focuses on complexity of inter-species communication, even when both parties are intelligent. Interesting and somewhat unusual focus, plus loved the style of writing.

[fuzztester]

Don't worry, Alt Samman & co. will soon create GAI - Genetically Advanced Intelligence, Octopus Edition, which will know how to manhandle us, 8 arms at a time.

[thrance]

Also featuring geneticaly modified super-intelligent octopuses, is "Manifold: Time" by Stephen Baxter.