Mariah Carey showed off her dramatic weight loss on Rosie O'Donnell's show, shedding over 70 pounds from her post-baby body.

After a series of sultry, anonymous campaign ads featuring a mysterious Madame X have gone viral on the Internet amassing over one million hits, we now know the svelte starlet featured is recent mother, Mariah Carey.

Carey, 41, is the third star, joining Carrie Fisher, to shed massive pounds this year from Jenny Craig, and she's not afraid to show it off. She appeared on Nov. 8 episode of The Rosie Show to debut her astonishing weight loss.

She's a while lot thinner, O'Donnell said as she introduced Carey from behind a curtain. She's never looked better.

That's when Carey was lowered onto the stage sitting on a sparkly crescent moon wearing a sexy ensemble.

Carey, who is married to Nick Cannon, is a mother of new twins, Monroe and Moroccan Scott Cannon. She said she lost the weight post-pregnancy from strict diet and some exercise through the Jenny Craig program, for which she is now a spokesperson.

The first week, I lost 40 lbs... of just water, Carey said, admitting she suffered from edema. It was just water, initially. When I started with the program, I lost at least 30 lbs. of weight that needed to be lost.

Carey said she not only wanted to lose the weight to regain her appearance, but because everyday tasks like going to the bathroom, were becoming difficult after the edema.

Edema was the probably the most painful thing I went through during my pregnancy. My legs looked three times the size of what my legs do right now. I thought I would never be the same person again, she said.

According to Carey, she lost most of the weight from dieting, as exercising was too risky after her C-section. The diet is 90 percent of it, she said.

Carey, who stands at 5'9, said she hasn't weighed herself since losing the weight.

I never weighed myself, she explains. People will think I'm a liar but it's true. This is another cliché phrase, I'm a big boned girl ... I'm tall and so I always weigh more.

Instead, she bases her weight loss progress on past outfits, admitting she is currently between a 4 or 6 in dress sizes.

 I would tend to go, 'Does this size dress fit me that I wore three years ago? I'm good, let's go.' I would go by what it looked like, how I felt, she admits.

Carey's appearance on The Rosie Show was the debut of the singer's body since the birth of her twins and also part of the Jenny Craig campaign, which promised to reveal the identity of the news spokeswoman on Nov. 8, 2011. The appearance also coincided with Rosie O'Donnell's Ready Set Go project to help 25 viewers lose weight.

As the new spokesperson for Jenny, the company's new name, Mariah Carey's latest song Make It Happen will be a part of the campaign as an inspiration to women.

The song is so fitting because a lot of people give up hope when they have had their kids and can't lose that 20 pounds or 40 pounds, or they have gone through issues with weight their entire lives. It becomes so frustrating and debilitating that you give up, Carey said.

View the slideshow to see before and after photos of Mariah Carey's weight loss and view the video below to see her new figure as the new spokesperon for Jenny.