They do say an actor can get lost in a role.
This week, Twilight fans and royal watchers alike were stunned when the first photo of Kristen Stewart in character as Princess Diana for the upcoming film Spencer was released and the resemblance proved to be rather remarkable.
And Stewart wasn't the only star to transform for a part as Justin Timberlake revealed he gained a serious amount of muscle for his new movie and HBO unveiled the first look at the late James Gandolfini's son in action as Tony Soprano for the upcoming prequel film.
Plus, Jennifer Aniston unveiled her hair change that has us craving summer already and Christina Anstead made a major step in her life following her recent split.
Check out the most surprising transformations of the week...