Piffany from Nodwick is always properly dressed no matter what. As with most such things in Nodwick, this was explicitly stuffed In-Universe just for fun, as the characters discover when robbed to the underwear:
Artax: Uh, Piffany? How'd you avoid this fashion "don't"?
Piffany: Easy! I'm wearing robes of modesty. It takes a wish to get them off!