If you're planning on transporting a mummified head on an upcoming trip, good news. The Transportation Security Administration is cool with the idea.
Based on my experiences sending faux human parts through international customs it's probably easier to buy a plane ticket and hand carry those props. And for safety's sake, remember to place the head between your knees in case of a crash. It may not improve your survivability, but it will certainly become a memorable story for the crash investigators.