There's a tutorial or two on sculpting bodies on the forum, I think one was called "creepy shelly" or something similar. Maybe someone who remembers the titles can post a link.
The basic way to do it is to create an armature using plastic bottles, wire shaped approximately to size, etc. Then you use clay and/or paper mache (or paper mache clay) to build out the final shape. Alternatively you could sculpt the shapes out of styrofoam - lots of posts about doing that, particularly by Terra.
The basic way to do it is to create an armature using plastic bottles, wire shaped approximately to size, etc. Then you use clay and/or paper mache (or paper mache clay) to build out the final shape. Alternatively you could sculpt the shapes out of styrofoam - lots of posts about doing that, particularly by Terra.