King Bowser Koopa Sr. is the leader and monarch of the Koopa Troop. Usually referred to as Bowser, he strives to be the ruler of all the Mushroom Kingdom. He has 8 children, 7 of which called the Koopalings, who have followed in his footsteps for years.
A young Magikoopa, he is a skilled Wizard and has no resentment or hatred of Bowser, seeing him as the rightful ruler of all things (even though it has been proved that that's wrong many times).
Dr. Eggman is a skilled scientist and was the leader of the Eggman Empire for a long period of time. He joined Bowser and his Koopa Troop at an unknown time, but has become the scientist of the Troop and has so far designed Mecha Mario and the Omega Doomship.
Kammy is the main wizard of the Koopa Troop but left Kamek to help Bowser while on vacation. She has shown much loyalty to Bowser and spies around different places to get information.
Ludwig is a skilled and the most powerfull Koopaling and the first one that was born. He has the most abilities of the Koopalings and knows many different techniques when fighting. He also breathe fire in the same level as his father. After Bowser Jr.'s appearance, he became the second leader of the Koopalings and the third-in-command.
Lemmy Koopa is the second Koopaling that was born. He is the smallest of them all, and loves to bounce on circus balls. He also creates them while fighting against the Mario Bros or any other threat.
Roy Koopa is the third Koopaling that was born. His ability is to create great earthquakes when stomping the ground, causing and enemy to stop for a few seconds.
Iggy Koopa is the fourth Koopaling that was born. He often enjoys creating machines to fight the Mario Bros.
Bowser Koopa Junior., informally known as Bowser Jr., is the youngest child of Bowser. It is not clear if he's a Koopaling or not, as in the New Super Mario Bros. Guide, he is known as a bothersome Koopaling, though he may not be a Koopaling due to debuting in Super Mario Sunshine instead of Super Mario Bros. 3. He is also the smallest, and is the leader of the Koopalings next to his older brother, Ludwig.
Basilisx is a Koopa that Dr. Eggman experimented on with a needle. He, like the creature he's named for, can turn people to stone just by being looked in the eye. He also has retractable razors in his hands, just like the Marvel Super Hero Wolverine.
They are Bowser's elite team of Koopas. Similar to Bowser, they have spines on their shell. Their armor tends to be gray, with the exception of Basilisx, who has a black shell. He leads the Koopatrols.