Mollusks are members of the invertebrate phylum Mollusca and contain more than 100,000 species. Some mollusks have shells like clams and snails, while larger mollusks have no bones at all like the cuttlefish, squid and octopus.
Imagine that someone is pursuing you down a dark alley. Do you run? Duck behind a trash bin? The mimic octopus doesn't sweat this kind of scenario: It just shape-shifts to disguise itself. You'll be surprised by the tricks it's got up its tentacles.
Squid are actually mollusks is although they look much different from their relatives the gastropods (snails) is and bivalves (clams). Check out this image gallery to learn more interesting squid facts.