The Box is a key item that appears in Paper Mario: The Thousand-Year Door.
The Box can only be obtained during McGoomba's trouble. McGoomba tells Mario to deliver the Box to Goomfrey in Rogueport. The true contents of the Box is never revealed as McGoomba doesn't want Mario or anyone else to know what's inside besides Goomfrey.
- The Box is similar to the Tape from Paper Mario and the You-Know-What from Super Paper Mario as all of these are side-quest items that Mario isn't allowed to know the contents of.