Mariah Careyyour new $18 million American Idol judge — has had her wacky moments.

But when she takes her chair in next season’s Idol, as one of the show’s three judges, 42-year-old Carey isn’t expected to be a particularly wacky judge, Idol experts say.

Instead, she will be — if anything — hard, critical of contestants with her high bar of singing skills.

What do the experts say?

“What I’m hoping from her, is that she has the potential to be a little bit of a villainess,” Lyndsey Parker, Idol beat reporter and expert for Yahoo!, told Celebuzz, hours after Carey was announced as the new judge.

“I don’t see her being like Steven [Tyler] and J.Lo and telling everyone they’re nice and wonderful and beautiful. I see her as being as kind of a tough broad who really shoots straight.”

Parker noted about the prospect of seeing a wacky Carey:

Carey’s name was floated for weeks as the next likely Idol judge — and here we are. Carey, one of music’s best selling performers of all time, is set to reportedly earn at least $17 million for next season, the Huffington Post has reported — more than her predecessor J.Lo made.

It is her first major foray into the public spotlight for Carey since having twins last year, Moroccan and Monroe. Carey told 20/20 last year that it was a difficult pregnancy, at 40 years of age.

Need a freshener-up on a few of Carey’s wackier moments?

In 1997, Carey said she feels as if butterflies follow her around, while promoting her CD, “Butterfly.”

In a 2011 appearance on HSN, Carey was particularly loose, cracking wise and waxing emotional after having babies. Carey said she was going to “have a fragrant moment” — and been trying to dress “camouflagian” while pregnant. Carey also said she was 47 weeks pregnant — an apparent attempt at exaggerating how intense her pregnancy was.

Carey memorably described some of her pieces as “kind of pow.”

Not Kooky For  ”Years”

Another inveterate Idol watcher, The Hollywood Reporter‘s Shirley Halperin, who wrote the book American Idol: Celebrating 10 Years (Your Offical Backstage Pass), describes Carey as not so much a wild card now, as a reasonable fit for the show’s aging fanbase.

“She hasn’t had really insane behavior in years,” Halperin told Celebuzz.

“I don’t think we can expect someone who is kooky for the sake of being kooky. Mariah has a very quirky personality that doesn’t come out in the public too often. You see it come out a little on her Twitter or cutesey inteviews with Nick Cannon.

“But we really haven’t seen her in this role yet,” Halperin added.

“She brings credibility, she brings devotion, [and] she should be a really good fit,” Halperin said. “She can be kooky — she can be like the Paula [Abdul] of the panel. We really don’t know what we’re going to get, which I think is kind of cool.”

Catch one of Carey’s wackier moments — from 2011, showing her jewelry and clothing products on HSN. Do you think Mariah is going to be a wacky judge?