Found only in the Boggly Woods in Paper Mario: The Thousand-Year Door, the Mystic Egg is from an unknown creature. It is given to Mario by Petuni, Punio's little sister. Mario will receive a Mystic Egg by playing the game "Stump Petuni" with the young Puni. Like in its prequel, the egg recovers five HP and may be used in all sorts of recipes.
As seen in the image, it is pale white-gray egg, like many things in Boggly Woods, and has two light black (dark gray) horizontal stripes on its sides; another effect on Boggly Woods' objects and creatures.
 Names in Other Languages
||Bubu Egg ("Bubu" is the German term for Puni)