Koopa Bros.

The Koopa Bros., also called the Ninjakoopas, are four Koopa Troopas who wear ninja gear and fight Mario, Goombario, Kooper and Bombette for Eldstar, the first Star Spirit in Paper Mario. They resemble the Teenage Mutant Ninja Turtles. Their names, which coorespond with the colors of their shells and their ninja gear, are Red, Yellow, Black and Green. They live in a fortress which was once the home for the Bob-ombs. They first fight Mario and company using the mediocre version of Mecha Bowser.

Rank
Officially, Red is the leader of the Koopa Bros. and the rank of the other three Koopa Bros. is not known. However, it can be presumed that the their rank is based on their position in their tower formation, the top having the highest rank. If so, then Red is the leader, Black is second in command, followed by Yellow with Green the lowest.

The Koopa Bros. are said to have been normal peaceful Koopas who defected to Bowser's side looking for adventure. Kammy Koopa is said to have a crush on them.

Origin
The Koopa Bros.' first appearance was surprisingly not in a video game, but rather in Volume 1, Chapter 13 of the Super Mario Kun manga. This was back in 1991, years before the Nintendo 64 even existed. As Mario, Luigi, and Yoshi travel in a world full of moving platforms, they stumble upon a pipe. The pipe turns out to be the Koopa Bros. in disguise, and they attacked the three heroes immediately. The Koopas throw shell-like shurikens, and then turn into Princess Peach imposters. Mario almost falls for this trick, but notices a shell on the fake Peach's back, and quickly disposes the Koopa Bros. The Koopa Bros. do not return until Super Mario Kun adapts Paper Mario.