The Koopalings(see how it doesn't include Bowser Jr.)
'The 'Koopalings are the children of Bowser. They first apperared in Super Mario Bros. 3, with one of them in each world being the boss of the world and transforming the kings there into different forms. Bowser Jr. is not a koopaling, though is the leader of the koopalings, while Ludwig Von Koopa is second in command and is the oldest Koopaling. Most of them have their names based on famous composers.