Bowser Jr.

Bowser Jr., known in Japan as Koopa Jr. (not to be confused with Baby Bowser in Super Mario World 2), is the eighth and youngest child of Bowser that debuted in Super Mario Sunshine.

Appearance
Bowser Jr. shares many physical similarities with his father, with the main differences being a red ponytail as opposed to Bowser's mane, small black beady eyes, a more rounded snout, and a single sharp tooth visible in his mouth--features which, along with his body shape, make him look almost identical to Bowser himself at a younger age. He wears a kerchief constantly. It was originally a drawing of Mario's distinctive nose and mustache, but it is later replaced with a set of sharp teeth.

Super Mario Sunshine
Bowser Jr. debuted in the Nintendo GameCube-game Super Mario Sunshine. In it, Bowser Jr. uses a magic paintbrush, invented by Professor E. Gadd, and a special kerchief to transform into a translucent blue doppelgänger of Mario, Shadow Mario, who vandalizes Isle Delfino, tricking the native people into believing that Mario himself is to blame. He does this to Mario because Bowser tells him that Princess Peach is his mother, and that Mario has kidnapped her. Bowser Jr. kidnaps her himself, and is eventually defeated along with Bowser. He realized that Princess Peach isn't his mother before Bowser decided to tell him, but he still refers to Peach as "Mama" sometimes in later games, such as when he challenges Princess Peach to a game in Mario Superstar Baseball.

New Super Mario Bros.
In New Super Mario Bros. and New Super Mario Bros. Wii, he is once again the main antagonist and kidnaps Princess Peach. He drags Peach around through different worlds as Mario chases him. Interestingly enough, Bowser is the boss of the first castle and not Bowser Jr. Once Bowser is defeated (plunged into lava) apparently, Bowser Jr. finds the time to go back and get his dad. Bowser Jr. revives his dad in a potion and fights alongside him in the final castle (World 8) by throwing shells at you.

Super Mario Galaxy
Bowser Jr. appears in Super Mario Galaxy as a boss. He arrives in a tiny ship at the end of his airship and fires cannonballs at you while you fight Koopa Troopas. If you throw a Koopa's shell at his ship, he will start firing homing-Bullet Bills. Hit it again and a Magikoopa will appear. Hit it one more time and fireballs will start flying out from it. Three more hits and it explodes (Bowser Jr. gets away).

Super Mario Sluggers
He appears in Super Mario Sluggers as the enemy of story mode and a playable character.

Mario Strikers Charged
In Mario Strikers Charged he is the champion of the Fire Cup. After beating the cup players will unlock Bowser Jr. as a playable character. He is good at shooting and passing and bad at everything else. His special is Sonic Scream, in which he leans forward and screams, shrinking any characters in range (including his own teammates).

Bowser_Jr. Bowser_Jr. Bowser_Jr.