The final model I have created can be viewed on the 123D Creature Gallery.
The final model can become a 3D print, for example with IMaterialise or a cardboard print with 123D Make. These can then be displayed on the wall as a Halloween decoration.
Step 1: The Skeleton
Once I decided how I wanted the design to look I began with selecting the 'create new' button and altering the skeleton. To begin with you are given a very basic shape to play around with. You can create and remove appendages and manipulate these by moving , shaping, posing and scaling, however the symmetry of the skeleton cannot be changed/removed.
For this design I deleted the legs first before using the shape tool to increase the general size of the model. At this point you do not need to worry too much about finer work, such as the eyes, ears and nose, as this can be accomplished later.
One must keep in mind that if you make this too complicated to begin with it can limit the sculpting detail and may even refuse to 'bake' at the next stage of development.
It may seem obvious but remember to keep saving your work or you may be disappointed to find your work is not up to date.