Call it a case of mistaken identity. When it comes to camouflage, chameleons get all the attention. But the often-overlooked cuttlefish is the real master of disguise. Cousins of the squid and octopus, cuttlefish are among the most unusual animals on our planet. These shape-shifting creatures can hypnotize their prey, impersonate the opposite sex and even kill with lightning-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. Cuttlefish also have one of the largest brain-to-body ratios among the invertebrates. With stunning underwater footage and in-depth expert interviews, NOVA gets up close and personal with this astonishing brainy bunch.