Grand Green Star Coin
From the Super Mario Wiki
A Grand Green Star Coin is a Skill Item in Puzzle & Dragons: Super Mario Bros. Edition. It raises the Skill levels of teammates whose Skill levels have reached level 4 using Green Star Coins such as most forms of Luigi, Spinies, and all types/forms of Bullet Bills, Wigglers, Chain Chomps and Flame Chomps. Grand Green Star Coins can be obtained by opening up ? Blocks; winning them from the Lucky ? Blocks game in Toad Houses; or from defeating "Flutter & Flame Chomp", "Chain Chomp & Flame Chomps" and King Bills with a 10+ Combo attack.