Hannigan, who played sidekick-turned-witch Willow Rosenberg, was revealing behind-the-scenes secrets about the show on 'Bravo's Watch What Happens Live' on Wednesday, Us Magazine reported.
When asked who according to her was most annoyed to be on the series by the end of the show's run, the 39-year-old quickly replied, "Sarah".
She clarified that Gellar "had a big career going" and that "it was a lot of work".
But in another segment of the show, the 'American Pie' actress revealed that Gellar, 36, grew tired of the show much sooner than that.
When asked in which season Gellar officially started to hate doing Buffy, Hannigan answered, 'three'.
--ANI (Posted on 11-05-2013)