The Midge Mallet (called the Minor Mallet in the 3D remake) is an item in Secret of Mana. The elder of Dwarf Village gives it to the party if they talk to him at any point after Gemma tells them to go to the Upper Land.
When used on a party member, the Midge Mallet inflicts or cures the "pygmized" status (i.e. shrinks and enlarges a party member). It can be used an infinite number of times.