Koopa Corps is an Enemy Attack used by Bowser in Mario & Luigi: Bowser's Inside Story. When Bowser uses this move, a ball of Koopas will appear in his hand. Then, Bowser will retreat into his shell, and several Koopa Shells will appear and bounce off a random enemy, causing damage. The player must then move Bowser up and down with the stylus, hitting the Koopa shells back and forth. The shells will get faster with each hit, and more shells will come in. This attack costs 10 SP and is unlocked after Bowser frees the Koopas.