The Koopa Troopa is also the first enemy with defense to appear in the game. This variation is slightly stronger than the Paper Mario variety, since this one has more attack power. In this game, the evil Koopa Troopas are first seen in the path to Shhwonk Fortress in Petal Meadows. It is also mentioned that a heroic Koopa, presumably a Koopa Troopa, was one of the original four heroes who defeated the Shadow Queen this Koopa's spirit is encountered at Keelhaul Key, as one of the four Black Chest Demons. Mario once again receives a Koopa Troopa partner, Koops. These "good" Koopa Troopas in this game are more true to the original Koopa Troopa appearance, with green shells and no shades or collars. The "good" Koopa Troopas of Paper Mario: The Thousand-Year Door live in Petalburg. In fact Bowser himself may encounter some Koopa Troopas during the parts of the game where he can be played as, though they all run away from Bowser when he approaches them.
The red-shelled sunglasses-wearing gangster style of Koopa Troopa was carried over to Paper Mario: The Thousand-Year Door as common enemies, despite Bowser not being the main antagonist of that game. He also makes a very small cameo in the sequel Paper Mario: The Thousand-Year Door. Troopa, who constantly stalks Mario and his allies to pick fights with them for intruding on his playground early in the game. There is also a baby Koopa Troopa by the name of Jr. One Koopa Troopa, Kooper, joins Mario's party to aid him in his fight against Bowser after Mario gets his shell back from the Fuzzies. After Mario and Goombario get rid of all the Fuzzies they become quite popular in the village (the Koopa Troopas even sends a letter to Mario later in the game, thanking him and apologizing for not rewarding him). The "good" Koopa Troopas all live in Koopa Village, a place which is overrun by Fuzzies at one point in the game. It is also the first enemy to make the First Strike and if Mario gets hits outside battle with this enemy, the player cannot use the action command meaning Mario will have to take damage. In this game, Koopa Troopas are shown to be quite resilient, as they have a fair defense (full damage can only be dealt once they are flipped onto their backs) and have the ability to withdraw into their shells and shoot themselves at their opponents. These Koopa Troopas aid Bowser in his plot to kidnap Princess Peach. All of the enemy Koopa Troopas in this game have red shells, a pair of sunglasses, and spiked, black arm bands and collars, like Bowser. Several Koopa Troopas appear in Paper Mario, both as enemies and allies. This could also be quite confusing because in Paper Mario: Sticker Star, and Color Splash there are no friendly koopas. These enemies are also in Paper Mario Sticker Star but these Koopas appear green and without sunglasses.
This also drops their defense value to 0.
If a jump attack is used against these foes, they are flipped onto their back for two turns, during which they cannot attack. While battling, a Koopa Troopa will use its Shell Toss attack to slam into Mario or his partner. They also appear as enemies, albeit wearing a spiked ring around their neck and shades. 2.2 Paper Mario: The Thousand-Year Door.