Toadstool's ???

Toadstool's ??? is a mysterious object that belongs to Princess Peach in the game Super Mario RPG: Legend of the Seven Stars. Apparently, the object is something very private and personal to Peach. No one except Peach and her grandmother is supposed to know about it and/or see it.

Toadstool's ??? is in between a blue chair and the fireplace in the back of Peach's room in the castle of the Mushroom Kingdom. When Mario first looks at it, Peach's grandmother rushes over to Mario and offers him a Mushroom if he'll mind his own business. If Mario looks at the object after Peach joins Mario's party, the princess will scold the plumber, saying that he does not respect her personal, private belongings.

Trivia

 * In Japan, this mysterious object is known as "Peach's XXX".