Crystal Ball
The Crystal Ball is a, well, crystal ball that has been featured in many games throughout the Mario series. It was first seen in Super Mario Brothers 2. Birdo spits it out after being defeated, and grabbing it opens the Hawkshead to the next level. Years later it's seen again in Paper Mario as the main magic tool for Merlon's family, there's also the red crystal ball, the Ultra Stone, for Ultra ranking Mario's partners. The Ultra Stone is also seen with Merlon in Paper Mario: The Thousand Year Door.
Madame Clairvoya used it to see the furture, and other things in Luigi's Mansion. It was seen once more in Mario Party 6, in the Seer Terror mini-game. Bowser used to see a player's "future" which usually was something bad. Occasionly, however, the player received Coins or a Mushroom. All of this was just for fun however, and had no effect on gameplay.
