With three hearts and blue blood, its gelatinous body unconstrained by jointed limbs or gravity, the octopus seems to be an alien, an inhabitant of another world. It's baggy, boneless body sprouts eight arms covered with thousands of suckers--suckers that can taste as well as feel. The octopus also has the powers of a superhero: it can shape-shift, change color, squirt ink, pour itself through the tiniest of openings, or jet away through the sea...