When you are building your tabletop castle you may get carried away with all the alcoves, plasterwork, gargoyles and other medieval gubbinz. Real castles were often way much simpler than that.
Usually after assembling models, particularly plastic ones, we are left with a handful of spare parts. Don't get rid of them as they may one day become a glorious addition to a new terrain piece or converted model »
Folks at Games Workshop love to put skulls all over anything. We in Central Europe understand their liking. It comes from an ancient Christian invocation: Terminus nulli cedo - The end (Death) bows to no one »