Please be sure to read the entire Instructable before posting questions! And remember..google is your friend :)
EDIT, october 2010: I was introduced to something called Magic Sculpt by a prop building colleague. I would highly recommend using that instead of the super sculpey i originally used for the sculpt. Magic Sculpt mixes together like an epoxy but is used like clay. You have a 2-3 hour window to work with it and it can be smoothed with water. It is tougher than sculpey and you do not have to use a hair dryer on it. It is not liable to crack like sculpey can. It will also stick to surfaces much better than sculpey.
Drawback: It is VERY heavy! It is more difficult to get fine detail with this stuff.
Where to buy: amazon.com has it as well as a few places online
Step 1: Carve out the face, add some features
Foam taxidermy form ( black bear or grizzly bear depending on size you want)
Please note! If you have issues with buying a taxidermy form, you can carve a basic form out of rigid insulation foam. I chose to use a bear form to save time. I don't have a tutorial on how to make a rigid foam carving, sorry. It's the pink stuff you can buy at Home Depot but i don't have any more info for that.
I also apologize for not having a "start" image for the bear form. I made this project without the intention of making it into an Instructable until after i was well into it.
Dremel or carve off the nose and drill a hole for glass eyes to be set into. Carve out where ever you are going to add sculpey and change the shape of the face. Bears have long droopy lips so you might want to shave them off so you can add your own snarly ones.I bought a form with an open mouth...the lower jaw is separate so you don't see it in these photos. Don't add your jaw until you sculpt all of the teeth first!
Add your sculpey. You may want to anchor longer parts into the foam with thick armature wire. Please note this on the pink clay version. Sculpt away! Remember adding fur will add some bulk to the sculpt so try not to make things too thick as far as the snout/facial muscles go.