Mortarboard

A mortarboard is a special type of hat worn by scholars during special ceremonies such as graduations. In mainstream Smurfs media and in the EMPATH: The Luckiest Smurf story "The Great Book Of Answers", Brainy is seen wearing a mortarboard as well as a scholar's robe, with his explanation being that it keeps the spiders out of his nose while he is living in the Old Tower.