Cog (Paper Mario: The Thousand-Year Door)
From the Super Mario Wiki
A Cog is an item in Paper Mario: The Thousand-Year Door. It is found in the X-Naut Fortress, on top of a shelf in the room with the Yux experiments. Mario reaches it by going through a vent. It can be returned to the prize-grabber crane machine on the first sub-level, allowing Mario to activate the crane. The crane is in a strange room with fancy devices, and a platform covered in prizes. Mario can work the crane by pressing to go to the left and pressing to go back. The Feeling Fine badge and a Star Piece can be obtained on the platform, along with some coins.