Impenetrable Cookie

the Impenetrable Cookie is a treasure in Pikmin 2 that is actually a chocolate cookie. It is found inside of a Puffy Blowhog on the 7th sublevel of the Cavern of Chaos. It is the 29th treasure on the List of Pikmin 2 treasures.

Captain Olimar's Journal
"As I grow older, I've observed that I am becoming crankier. Today, I flew off the handle over a trifling matter. I feel like such a fool... I must learn to control my cantankerous temper! I can't allow my bad attitude to erode teamwork on this vital mission."

Sales Pitch
"It is hard. Really hard. Too hard. So hard that you're not sure you can eat it, even though you must. This hard snack is infused with the essence of stubbornness, and you are powerless to resist it."