As I'm sure you know, when there was some historical quip or bit of sarcasm offered and no one knew who said it, it was credited to 'a wag.' I always thought that a great expression.

My favorite was from Victorian times. Victoria had mourned Albert a couple of years, and most thought that was plenty long enough - time to get back to being Queen.

Someone was critical enough to post a small placard on the gates of Buckingham Palace saying 'These Premises to Let.'

Since no one admitted to it, it was credited to 'a wag,' of course.