The Koopa Bros. are a group of four koopas who work for Bowser. They are very much invested in finding "righteous gems of power" at whatever cost and don't hesitate to fight Mario if they see him.

The Koopa Bros. are all very similar in personality with slight differences between them. Red, the leader, is very bossy, taking leadership by force. Yellow is Red's right hand man, handling all of the technical stuff like holding onto the Radar. Black and Green are the lowest of the four but are still essential to the team.

The Koopa Bros. have voices akin to stereotypical surfers and/or hippies. Since there are four of them, there will be four positions open for this meaning that you can audition once and get a chance at four characters.