A simple thing really if you put thought into it,
1.You take a corps not decayed much and you slice it into sections for the joints.
2.You remove anything that will decay except flesh.
3. Replace bones with metal or wooden rods.
4. Add the ball joints to your specimen in the slices you made in the sections (the slices should be made where the limbs bend naturaly.)
5. Coat flesh with a supliment to preserve and protect it.
6. Add tubes for poison to pass through, (A very affective one would be a Mist maker you can buy from a sports store it has a long hose and it can me turned on and off.)
7. conect the pieces back into a full object.
8. Enjoy your masterpiece.