My son wants to be a toothbrush for Halloween. I am not super crafty—though I did successfully make him into a giant cocktail shrimp a few years ago—but I can sew. I'm kind of puzzling as to how to go about this. Any suggestions? My initial thought was a giant block of foam or maybe styrofoam that could be placed over his head... (He is about 4'9" if that makes a difference.)