The Pacific Northwest tree octopus (Octopus paxarbolis) can be found in the temperate rainforests of the Olympic Peninsula on the west coast of North America...These solitary cephalopods reach an average size (measured from arm-tip to mantle-tip,) of 30-33 cm. Unlike most other cephalopods, tree octopuses are amphibious, spending only their early life and the period of their mating season in their ancestral aquatic environment.