Bowser Jr. is the secondary antagonist of the Mario franchise who first appear in Super Mario Sunshine serving as the central antagonist while also disguising himself as Shadow Mario.
He is the son of Bowser as well as also the second-in-command of the Koopa Troop who also helps his father with his plans.
In Super Mario Sunshine, he was voiced by Dorlores Rogers and is now currently voiced by Caety Saigoian.