Although `` Baby Bowser '' , the infant version of Bowser whose design bears a strong resemblance to Bowser Jr. , had previously appeared in Super Mario World 2 : Yoshi 's Island and Yoshi 's Story , Jr. himself first appeared in Super Mario Sunshine , where he disrupted Mario 's vacation with Princess Peach by painting the island of Isle Delfino with goop and then kidnapping her by framing Mario , after his father Bowser tricked him into thinking that Peach was his mother which he had to protect .
Bowser Jr. first appears in Super Mario Sunshine , where he disturbs Mario 's vacation with Princess Peach on Delfino Isle by making the island dirty and kidnapping Peach .