An Octopus
I was walking past this thing completely oblivious and was startled when it squirted water at me, so I stopped and filmed it for an incredibly long video clip (in which you can see it do the color camouflage thing a few times while it half-assedly looks for crabs to harass).
Although Australia is home to the world’s most venomous octopus species (which according to wiki is even more dangerous to humans than I had realized), this is not one of those… not that I would try to pick it up to find out.
The crabs at the beginning seem pretty cheeky.
Awesome video, I never realized they came up out of the water like that.