This is my prosthetic process for the brand from Mad max fury road! I made four from this mold, once you have the process down its really easy. Shown here on my arm, actual placement will be the back of the neck.
1) gather reference photos
2)decide the size of the prosthetic
3) make the shape you want out of air dry clay
4) pour a plaster mold
5) dig out all the clay
6) (prime the mold with Vaseline)
7) pour in liquid latex, might want to do this in layers.
8) remove prosthetic from mold.
9) use makeup to paint prosthetic, trim up edges.
10) add color details, use with hairspray to seal, attach with spirit gum.