After being defeated by the Mario brothers, her soul is absorbed by Fawful's Vaccum Helmet and transfered into Bowser's body thus creating the being known as Bowletta.
In the game, she stole Princess Peach's voice by using some sort of gas to take it. The reason she stole it is because the Beanstar, an object that can grant wishes, was cast into a deep sleep, and can only be awakened by the most beautiful voice, which only Peach possesses. After Cackletta stole the Princess' voice, she went to Woohoo Hooniversity, where she planned to awake the Beanstar. However, when Cackletta used Peach-bots with Peach's voice to wake the Beanstar, it instead went berserk and fell into the basement (and eventually broke into four pieces when the MarioBros., Popple, and Rookie, aka Bowser, were holding onto it as it rose into the sky). Cackletta then battled the Mario Bros., and lost. Fawful then absorbs Cackletta's remaining energy with his helmet in order to save her, and proceeds to attack the Mario Bros., only to be thwarted by Prince Peasley, the prince of the Beanbean Kingdom.
It turned out that Prince Peasley predicted her plot, and so he traveled to the Mushroom Kingdom to warn Peach of Cackletta's plan. So instead of getting Peach's voice, she got Birdo's voice instead, as Birdo posed as Peach during the attack. Meanwhile, somewhere in Stardust Fields, Fawful and Cackletta find Bowser unconscious, and Cackletta possessed him, becoming Bowletta. While Luigi was at Guffawha Ruins to get Crabbie Grass to cure Mario's Bean Fever, Bowletta went to Little Fungitown, a Mushroom Kingdom immigrant town where Peach and Mario are, to kidnap Peach. It is here that Bowletta reveals herself, and when Mario and Luigi return to Beanbean Castle, Bowletta gives them a message, stating that if they want to see Peach again, they must retrieve the Beanstar's pieces and reassemble it. After collecting the Beanstar's pieces and restoring it, Bowletta sends another message, telling them that the exchange point will be at Joke's End. Prince Peasley gave the Mario Bros. a fake Beanstar for the exchange so Bowletta won't get the real Beanstar.
Unfortunately, when Luigi was about to make the exchange, Fawful saw through the disguise and took the real Beanstar without handing Peach back. Mario comes up with a plan however, and he eventually confronts Bowletta with another Princess Peach. Bowletta, thinking she was deceived again, drops the Peach she had and captures the other Peach. At the Koopa Cruiser, Bowletta asks Peach why she keeps covering her mouth. Peach doesn't comply, so Bowletta scares Peach, revealing that this Peach had a mustache. It is soon revealed that the Peach Bowletta kidnapped was actually Luigi in disguise. As Luigi escapes, he takes the Beanstar with him, leaving Bowletta tricked once again. Instead of pursuing him however, she instead goes to the Mushroom Kingdom and rounds up Bowser's army, including the Koopalings.
She then launches a full scale assault against Beanbean Castle from Bowser's Castle. The Mario Bros. (with help from Blablanadon, a pterosaur-like creature) board Bowser's Castle, and after defeating each Koopaling one by one, enter Bowletta's room. After giving a little speech to the bros., they battle. For a moment, it seemed like she was defeated, until a Time Bob-omb approaches the bros. and explodes, K.O.ing them. She then taunts them, and sucks them into her stomach. Inside Bowletta's stomach, the Mario Bros., barely conscious, battle Cackletta's spirit, and defeat her once and for all. This causes Bowletta to spit the bros. out, and Cackletta's spirit is soon seen disappearing from existence, returning Bowser to normal.