Common Octopus inside a bottle. Since the beaks of Octopi are the only hard parts of their body, they can fit through any opening at least about a square centimeter to a square inch in size depending on the size of the octopus.
Photograph by Luis Miguel Cortes, My Shot
The common octopus is anything but ordinary. This most intelligent of the invertebrates uses an amazing suite of abilities to avoid predators like sharks, eels, and dolphins. A master of camouflage, the octopus can change color and shape to remain unseen, and release a “smoke screen” of black ink when spotted. Even if an octopus has been nabbed, the game isn’t over—it can simply shed an arm to escape trouble and regrow the appendage later.