With Lisa as a start point, here is our Skull Ring.
Uploaded here a 22mm and 18mm version (internal diameter).
Prints with minimal supports, standing on it's chin.
Looks great in Glow in the Dark or colour change filament.
See http://www.3dmigos.net/product-category/halloween/ for the rest of my Halloween products.
I made my own low poly version of Liza, and sunk it's eye sockets deeper.
Blended it with a handy ring blank I had kicking about...