If it were me, I would get a prothetic skull made and then have fun with it. You could:
1. Put a little trap door in the side and randomly pull things out while talking to someone, like little birds or loose change.
2. Make a prothetic that looks like an exposed brain. I would also make it throb. Then go into a pharmacy and ask for the aisle where they have something for a bad headache.
3. Instead of a fake exposed brain, it could look like a bunch of circuits. Then ride around on buses and tell people you are a robot from the future.
4. You could have a real arrow go through the prosthetic. When people tell you to stop fooling around with that old gag, you could pull out the real arrow and watch women faint.
If you ever get half your head lopped off, you’re set.