Battle Trunks

From the Super Mario Wiki

Battle Trunks are a type of clothing found in Paper Mario: The Thousand-Year Door. After Mario took on Jolene's trouble, he discovered that over a dozen of these smelly shorts litter the storage room in the Glitz Pit. As such, Mario had to pick them up, then deliver them to Goomfrey (the Goomba outside of Professor Frankly's house in Rogueport that Goombella did state was the kind of person who can make problems disappear) to complete the trouble.