How do I do a dog- shaped cake, like this on the picture I attached below? I'm wondering how many cakes shall I bake to carve the dog and how big those cakes should be?

Well..When I did my 3D Dog I used 2-8 inch rounds and 2-8 inch half balls.(You can find a 8 inch half ball inside the Betty Crocker bake N fill pan set).I used these for the top of head and rump.I baked 2-6 inch rounds and cut them on half and laid them side by side for the body.I baked 2 mini wonder molds and cut them from top to bottom for the hind legs.Then I used spare cake from 6 inch rounds to make paws etc...I then carved the face,eyes to look more realistic.Then I covered in buttercream with tip 234.I aprbrushed the spots etc..Made a fondat tongue etc..Have a look in my photos...

I hope the link works. Here are instructions and amounts.

http://media.cakecentral.com//files/puppy_cake__1__942.pdf