AJS Metals Miniature Skulls
AJS Miniatures is owned by the famous Andy Slater of TerraGenesis fame.
These skulls work well for converting miniatures in the 28mm scale. They come 12 to a sprue and are cast in white metal. For Warmachine, it would be easy to do a head swamp and convert a miniature into a Cryx Thrall. For Warhammer 40K, the skulls could adorn the walls and doors of buildings.
These skulls are very handy to have and I would recommend adding them to your bits collection.