Green Star

A Green Power Star is a green-colored Power Star that can be found in Super Mario Galaxy. Only three Green Power Stars are known to exist, all of which are hidden away in certain galaxies. Collecting all three of them will grant Mario access to the three Trial Galaxies, those being the Rolling Gizmo Galaxy, the Loopdeeswoop Galaxy, and the Bubble Blast Galaxy. Green Lumas will grow up to turn into Green Power Stars.

One Green Power Star is hidden in the Buoy Base Galaxy, another is hidden in the Dusty Dune Galaxy, and the other one is eventually discovered by Luigi in the Battlerock Galaxy.