I got an anatomical model of a human skull and a whole load of food grade silicone. After putty-ing up the fiddly details and finding suitable containers for the skull and jaw I poured the silicone around them and left it for 48 hours to set. After de-molding the originals I trimmed the molds down to make them more flexible. I cast the jaw and face out of milk chocolate and used dental tools to carve some of the detail back in.
This would be a fun item to have for Halloween but I’m not sure if it would need to be human sized. Maybe we could use the shrunken pygmy skulls instead? Melanesia and the Amazon basin people preserved the heads of their enemies by removing the skull, then boiling down the skin and flesh (I love the collection at London’s Horniman Museum). It’s thought these objects had religious significance – that shrinking the head of anyone you killed in battle stopped their soul from coming back to seek revenge.