Mary O., the chick in the manual who gives you a guide on the game and even creates her own courses, is now available as a mystery mushroom costume in Super Mario Maker. Clear the latest event course online and it’s yours!

If you’re interested in checking out her levels, she has her own Miiverse profile with course IDs there. These levels are unrelated to the Mary O. costume.
Nintendo shared this news via Twitter along with a comic series featuring Mary O. and her companion, Yamamura. The comics look like little more than some basic course creation tips with Mary and a bird who is occasionally snarky, but if that that’s your thing—by all means, indulge.