The Fright Mask is an item that appears in Paper Mario: The Thousand-Year Door. This is an uncommon item that can bought in certain shops or found in certain areas. The Fright Mask itself resembles Bowser's face.
With the Fright Mask, it may scare all enemies away from the battle. If it works, the enemies that fled would only yield 1 Star Point while it may not work on others. Fright Masks are useless against bosses and should only be used against weaker enemies that can already yield 1 Star Point.