The visual alien form is superficial, the underlying cognitive process is very much the same, but different.

McGichrist write about the Master and the Emissary to explain the conscious and subconscious human brain. The octopus takes this to a whole new level with eight separate sub-brains, each a Markov blanket to itself as demonstrated when one gets severed. Unlike the tail of a drop-tail skink, the severed arm shows continuing evaluation and adjustment to its environment.

Is there a "what it is to be an octopuses arm", does it exhibit agency like a human? Most likely not but it blurs the boundary between organic and non-organic consciousness.

> Their evolutionary history is thought to go back 330 million years, far longer than mammals

That makes no sense.