Strange Sack

The Strange Sack is a sack that allows Mario and friends to carry up to 20 items in Paper Mario: The Thousand-Year Door. It is found on the 50th floor of the Pit of 100 Trials. It creates a better strategy for carrying items and having room for some Mario finds on his journey. Mario shouldn't plunge into the Pit early in the game, since it's possible to die in Levels 30s/40s.

It may be called the Strange Sack because it defies the laws of physics, since it can carry so many things in a small area.