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The Mario Key is an item in the game Super Mario 64 DS. The Mario Key is the key that unlocks the door that Mario is trapped behind and is the only character key required to beat the game. It is obtained by Yoshi after collecting eight Power Stars, entering the room behind the Princess's Rec Room, and defeating Goomboss inside the Mario portrait. The Mario Key was created by Bowser and given to Goomboss and his Goombas to trap Mario after they caught him. After the defeat of the Goombas, they retreat, leaving the key behind. The key is about the size of Mario, is made of gold with a large M in the center of it, and has a Mario's Cap on top of it, though the cap disappears upon collecting it. Once Yoshi retrieves this key and brings it to the door Mario is behind, Mario will be freed, and Mario's Caps appear inside courses if the player is someone other than Mario.