I am not sure if you buy classes from Craftsy or not but there is a class on there that show structure for sculpted cakes. This may be handy for you
http://www.craftsy.com/class/advanced-cake-sculpting-bobblehead-cakes/146?ct=sbqii-sqjuweho-qbb&ctp=146,43
I would use metal supports for the legs and have a wood base at the bottom of the body to support the cake.
Good Luck!
