In the climax, Berkeley tries to catch Thumbelina for Grundel as she leaves the wedding. But when the Fairy Prince arrived - Grundel is enraged that Berkeley failed to kill him, and knocks the Beetle out by humorously bashing his head in and battles Cornelius. In the credits, he returned to his normal, popstar life and got his wings back.
He reprises his role in the Spyro adventure, where a joke will be played on how Iago and Berkely sound very alike. He's not in cahoots with Maleficent or Mirage...or is he? no, he isn't.
Role outside the Series
He is also a reformed character in the Jaden's Adventures series by rtgoh1, cause he felt he's nothing more of a simpleton caught in the wrong crowd, and that Jaden Yuki saved him from Grundel.