'Hills' Stars Talk Heidi Montag's 'Shocking' Plastic Surgery

'She looks like Barbie,' Audrina Patridge tells MTV News of co-star's altered look in tonight's season premiere.

Heidi Montag has gone through some changes over five seasons of [url id="http://www.mtv.com/shows/the_hills/season_6/series.jhtml"]"The Hills."[/url] As the series starts its final season Tuesday night (April 27), fans will finally get the chance to see just what happened when Montag went home to Colorado to show her mom, Darlene, her biggest transformation yet.

"It's in the first episode of the sixth season," Audrina Patridge told MTV News of her co-star's extensive plastic surgery. "So everyone will get to watch and see [Heidi's] grand entrance, which is interesting, because none of us really knew what to expect, and when I saw her ... you know, I don't think she looks horrible — she looks like Barbie."

Kristin Cavallari said that, while she's spoken to Heidi about her new look, mom Darlene's response will likely have everyone buzzing. "My initial reaction to Heidi's plastic surgery was it was very shocking to think that she did so many different surgeries," Cavallari said. "But ... I've seen her and talked to her about it, and she seems very happy, which is, ultimately, the most important thing. And she looks good.

"I think it's talked about a lot on the show and everyone's reactions. It's supposed to be pretty intense," Cavallari said of Heidi's confrontation with her mother.

Heidi's sister-in-law, Stephanie Pratt, admitted she was initially surprised by the decision. "When I found out about Heidi's plastic surgery, it made sense why she didn't come to Christmas or Thanksgiving or any other holidays. A lot of questions were answered for me," she said. "If she feels better, I'm so happy that she feels secure. When a woman feels good about herself, that's the best feeling, so I'm really happy for her."

Are you looking forward to seeing how the "Hills" stars react to Heidi's new look? Tell us in the comments!

"The Hills: Final Season" premieres tonight at 10 p.m. ET/PT followed by "The City" at 10:30 p.m. ET/PT on MTV.