Koopa Troopa

Koopa Troopas are a tortoise-like species from the Mario franchise, in which they have first appeared in Super Mario Bros.. They are the main footsoldiers of the Koopa Troop, led by Bowser, and are one of the most common enemies, along with Goombas. However, several Mario spinoff titles feature friendly Koopas who are not enemies, and are sometimes featured as allies. Koopa Troopas appear in the crossover Mario & Sonic series, albeit with minor roles such as spectating certain Events, and their first Sega-related appearance is in the Wii version of Mario & Sonic at the Olympic Games. Koopas also appear throughout the Super Smash Bros. series.

Mario & Sonic at the Olympic Games
During the opening sequence of the Wii version of Mario & Sonic at the Olympic Games, Koopa Troopas can be seen as cameramen during the Archery and High Jump events, although they are not present in the playable events themselves. Koopa Troopas also appear in the crowds throughout the game.

Mario & Sonic at the Olympic Winter Games
A Koopa Troopa appears as a referee in Mario & Sonic at the Olympic Winter Games.

Mario & Sonic at the London 2012 Olympic Games
In the Nintendo 3DS version of Mario & Sonic at the London 2012 Olympic Games, a pair of Koopa Troopas are one of the opponents in Events that require pairs of characters to be used. However, the Koopa Troopas are never seen competing in the events.

Super Smash Bros. Brawl
Koopa Troopas appear as part of Bowser's army in Adventure Mode: The Subspace Emissary in Super Smash Bros. Brawl. Donkey Kong and Diddy Kong face many of them while attempting to take back the banana hoard, and a Koopa is actually the creature that stole the bananas in the first place (under Bowser's order). Diddy Kong, Fox McCloud, and Falco Lombardi also fight some Koopa Troopas while searching for the kidnapped Donkey Kong. Bowser last uses Koopa Troopas to attack Castle Dedede in order to steal the trophies that he had amassed. This is the last appearance of Koopa Troopas in the game. Koopa Troopas are not the most common enemies in this game (due to Bowser not being the main antagonist); Primids are actually the most frequently encountered enemies. In all the games where Koopa Troopas appear, their shells can't break, but in a cutscene where the Koopa Troopas steal Donkey Kong's banana hoard, it is shown that Donkey Kong can break their shells with his fist.

Super Smash Bros. for Nintendo 3DS
Koopa Troopas appear in Super Smash Bros. for Nintendo 3DS as enemies in Smash Run. They can attack the player by jumping at them, just like in Super Smash Bros. Brawl. After being defeated, they will become a shell that can be thrown like an item, but the Koopa Troopa will come back out after a short time, even if the shell is still in the player's hand.

Super Smash Bros. Ultimate
A green Koopa Troopa appears as a Novice type support spirit in Super Smash Bros. Ultimate, taking one slot and equipping the fighter with a Green Shell at the start of a battle when used. In its spirit battle, the player faces Squirtle on the Golden Plains stage. The spirit's core can be used with an Old Man Lobber core and a support core to summon Tortimer's spirit.