okay I was wrong, it is adven68 and here is a link to see the rocking horse she made.
http://cakecentral.com/modules.php?name=coppermine&file=displayimage&meta=allby&uname=adven68&cat=0&pos=14
I made a 3D horse for my 8th birthday cake. Course, it was from regular icing so spread over the entire cake, but its the thought that counts....
If no other (more professional) help is forthcoming, I would look at websites with instructions for drawing horses begining with geometric shapes as a framework, (http://drawsketch.about.com/library/bl_step_horse1.htm)
then 3D it--e.g. the body is basically a large circle and a slightly smaller circle joned together, so 3D it and you have Large sphereical ball, cylinder bit, slightly smaller spherical ball. Neck and head are varying sized triangles with the tops chopped off, so you would make cones. Its easier to get the correct scale of bits this way than just starting with a lump and moulding. Lay all the bits out first so that you can be sure they are in the right proportion to each other, then smooth them together with a picture of a horse in front of you to get it as lifelike as possible.
I've checked out a few clay books from the library (don't have names, sorry), and I know sculpey has a new book, that may be of some help to you. It all depends on if you're looking for a "real" horse or somewhat animated. If you can some books they may be helpful.
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