Chances are that you will need more than one clay figure, in fact you'll probably need a small army.
Here's an inexpensive way to make 'clones' of your original sculpture.
Armature wire (1/16")
Van Aken Plastalina Clay
InstaMold Mold Making Compound
Baby Oil (Mineral Oil)
Double Boiler (or cooking pot and glass mixing bowl)
Paint and brushes
Imagination, patience and a video camera (optional)
Step 1: Draw your character!
For a full sized character aim to draw it about 9-14" in size.
In this tutorial Gromit (being a dog) was fairly short at about 9".
Make the drawing fairly simple, something that will be possible to sculpt in clay, and for which you can envisage a simple wire armature (skeleton).
Step 2: Give 'em some bones!
You will end up with 5 pieces of wire (2 arms, 2 legs, a torso), Assuming you are making a humanoid.
Each piece of wire will be double the length of the body part it represents. For the head leave a big loop in the torso wire, and put loops for the hands and feet.
After you have cut the wire to the right lengths and use the drill and pliers to twist them together.
Use the Sculpey to block out the chest, pelvis, hands and feet of the skeleton, and to hold the wire together. When you are done put the armature on a baking sheet and bake the Sculpey permanently hard in your home oven, 15-20 minutes at 275ÃÂºF. Remove and leave to cool.
Step 3: Sculpt your clay figure.
I won't talk you through this, but their are plenty of sites with good tips on sculpting clay:
If you already have a figure you wish to copy skip to the next step.