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Dark Koopas are purple-shelled Koopas that live in dark places underground. They first debut in Toad Town Tunnels in Paper Mario, where they sometimes grin and start to spin around when they attack, making their opponents dizzy. They are also stronger than regular Koopa Troopas. This is the only place in the game where they can be found, just like the Gloomba and their relatives.
Dark Koopas are also found in the Pit of 100 Trials in Paper Mario: The Thousand-Year Door, but in this game, they do not cause dizziness. Instead, they are merely stronger than regular Koopa Troopas, having their stats doubled, and slightly stronger than they were in Paper Mario. They are found in floors 31-39.
In Mario & Luigi: Bowser's Inside Story a different kind of Dark Koopa appears in the final battle with Dark Bowser, after his body grows large he'll throw a ball of dark enemies. Dark Koopas go into the shells and Bowser needs to push them into the other enemies up ahead.
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