Koopa Troopas, or Koopas for short, are a species of turtle. Koopas are often members of Bowser's army, and thus attack Mario, as shown in multiple Mario games.
In-game, Koopa shells can be ridden after being detached from the enemy's body. Without its shell, the Koopa will be shown in its underpants, and run around embarrassed. Shell-surfing protects Mario from several hazards such as lava burns and damage from weak enemies. The shell will break if it hits a wall, however.
In SuperMarioGlitchy4's bloopers, Koopas are minor characters that don’t appear that often, with the exception of Bowser, their leader. They are said to be very retarded and they like to call people fat. Their in-game behaviors are also used for comedy.
