Cuttlefish are one of the strangest animals on our planet. These shape-shifting creatures can hypnotize their prey, impersonate the opposite sex and even kill with lightening fast speed. More accomplished masters of disguise than any chameleon, they have an incredible ability to morph their skin color -- even their shape -- to blend into most any background. They have the largest brain-to-body ratio of all the invertebrates. But are they capable of learning and remembering complex tasks? With beautiful underwater footage and in-depth expert interviews, NOVA gets up close and personal with these bizarre and amazing animals.