The Patience Tester is a treasure in Pikmin 2 that is actually a can of Sun Luck water chestnuts. In the NTSC version, It is found on the 3rd sublevel of the Citadel of Spiders. In the PAL version, It is found on the 9th sublevel of the Hole of Heroes where it is inside a Fiery Bulblax. It is the 162th treasure on the List of Pikmin 2 treasures in the NTSC version and the 161th in the PAL version.
Captain Olimar's Journal
"Just looking at this sealed container makes me want to open it up! But opening it will decrease its value on the alien antiquities market. Maybe I'll just use my imaginary can opener and pretend to open it instead."
"This calls out to be opened, peeked inside, and tasted. This temptation-filled item is perfect for those who wish to test the strength of their resolve."