Batshoorm?

It was a purple mushroom, who's color reminded the princess of the Shroobs a bit. Red dots, purple 'head' and palish body. The odd part was it seemed to be smiling with little fangs and bat like wings.

Peach asked her advisers about what it did, and none of them knew what it was. And Mario was gone, off on another quick adventure or crossover, so she was on her own.

And she had been... a tad hungry today..., could one bite hurt?

"No, Bowser probably sent it. Or someone else. It'll make me a cute little bat and someone will take over the kingdom. Or something like that." Peach muttered as she went to the library.

And yet, hours of research still left no new info, or hints as to what it could do. Only that cooking power mushrooms could have strange effects on the results.

Once more, her stomach grumbled. That strange mushroom was looking pretty good...