A new costume update could be coming to Super Mario Maker fairly soon. A few players were able to snag the costume for Mashiko, also known as Mary O, the manual guide for Super Mario Maker. However, the outfit is no longer obtainable at this time.
Additionally, it appears that new Event Courses for Mashiko and Wolf Link also became available for a short amount of time earlier.
Super Mario Maker is available for the Wii U.