So what did Nightmare Moon/Luna do during her time on the moon?
Some say she was magically frozen in the center of it. Others believe that she lived on the surface, enjoying the darkness, made pony shaped sculptures from rocks and tended to her rock garden.
There is an old myth saying that once she spent weeks just running around all over the place, her tracks eventually forming giant letters saying "CELESTIA IS STUPID!" along with a crude caricature of Celestia's face...Now available on t-shirts at WeLoveFine.com. Licensed by Hasbro.