This is an updated Spinister head I made for Blunghole of the "Good Morning Cybertron" podcast. The head is designed specifically for the Hunt for the Decepticons Tomahawk mold. It has a 4mm socket for a ball joint attachment but I've also included an adapter peg with a shaft that fits up into the head and a 4mm ball on the other end if you want to 'bash it onto other figures.
I definitely recommend this in FUD material to maintain all the detail and so his "horns" don't warp or break. This is a 2-piece head so the eyes can be painted cleanly or the entire insert can be dyed for light piping.
This model is untested.