Credit: ary Evans/WARNER BROS TURNER ENTERTAINMENT/Ronald Grant/Everett Collection; Kevin Mazur/WireImage

Get her giant floating bubble ready!

Michelle Williams has been offered the role of Glinda, the Good Witch, in Oz: The Great and Powerful, according to the Hollywood Reporter. The prequel take on The Wizard of Oz already has James Franco and Mila Kunis signed on and is being directed by Sam Raimi.

The site reports that Rachel Weisz is in talks to play Evanora, the evil witch who wants to rule the land and tries to woo Kunis' character to the dark side. 

If the deal goes through for Williams, 30, she will play the powerful witch who teams up with Franco to defeat Evanora.