Though this little guy seems further along in its development from larval stage into juvenile stage than the cephalopods of a few weeks ago, it presents the same identification challenge. This is either a juvenile East Pacific red octopus, Octopus rubescens, or a juvenile giant Pacific octopus, Enteroctopus dofleini.
I didn't see the telltale "eyelashes" (papillae) of an East Pacific red octopus, so it could be a giant Pacific octopus, but it's hard to say. I'd like to believe it's a GPO that could grow as huge as the HRAP truck.
According to National Geographic, the largest Giant Pacific Octopus on record was 30 feet across and weighed more than 600 pounds. If an octopus of that size turns up in the tidepools, we won't have to worry about it getting trampled.