The Millennium Star is the name of two known star entities, one false and one who is the real. They both appeared in Mario Party 3.
The first Millennium Star is a silver, mustachioed star who will grant the wish of any player who passes his test. The Millennium Star fell on Peach’s Garden while Mario and his friends were resting. Mario and his friends argued about who would get the star, which resulted in Lakitu coming and suggesting that they have a contest to see who get the star.
So for all you fans of Mario Party 3, go download and build this thing!