Kingdom Animalia
Subphylum Invertebrata
Phylum Mollusca

Containing the classes:

They have soft bodies, consisting of a head, a visceral mass, and a foot (sometimes multiple feet -- but none of these feet have bones). Usually there's some type of shell to cover all of this (but octopi and squid are mollusks too {class Cephalopoda}). Most also have a radula ('psuedo-tongue') to help do work that the foot can't handle on its own. Most live in the water, although snails and slugs are also mollusks.