here's a start.
note diagram in lower right corner....
the board is not a normal shape but specially tapered toward the tail and has little wings for the knees.
then lower left corner -- side view of supports -- remember TWO of the front ones
then overlay on pic -- generally idea of how the supports go inside the cake.
ALL supports are copper or plastic tubing-- type used for WATER in a home (ie food grade) attach by drilling, screwing and using flanges. Curved supports for tail and arms will have to be copper so you can shape/bend them
Board is plywood.
tail & head -- RKT
main body -- i'd start w/ wonder mold and then build up w/ added pieces of cake from rounds or sheets.
legs -- squares of cake cut / fitted / carved -- should be very angular.
hide back support that hold ups tail-end by crafting a crushed car or building around it -- so it looks like he just wholloped it!