Rupoor
A Rupoor is a black Rupee-like item that appears in The Legend of Zelda: Phantom Hourglass. It is first encountered on the Ghost Ship, after one of the Cubus Sisters advises Link to gather treasure from one of two chests. Opening the chest that the Cubus sister recommends results in Link finding a black Rupee, or the Rupoor. Their only other appearances in the game are on Harrow Island, in which you can find 10, 50, and 100 Rupoor, and in a maze where instead of walls the maze is made of 10 Rupoor and 30 Rupoor pieces. The result of collecting a Rupoor is that its amount will subtracted from your wallet.