'The Voice': Mariah Carey Makes Her Grand Debut on Monday Night

Mariah Carey is coming to The Voice Monday, and the NBC show's contestants definitely didn't expect such an iconic singer as a knockout adviser.

In two promotional videos, the network shared ahead of the "We Belong Together" singer's debut, coaches Kelly Clarkson, Adam Levine and Jennifer Hudson revelled in the secret up their sleeve before bringing in Carey.

"They're gonna freak out!" Clarkson says.

"They're gonna bug out," Levine echoes.

Hudson adds, "They gonna lose they minds when they see her."

They weren't wrong. As the singers who have made it through to the knockout rounds turn the corner and see the pop diva sitting there, they all have various levels of breaking down, some falling to the floor, others shouting in surprise.

"Hi," Carey tells them with a smile in return, causing coach Blake Shelton to crack up.

But the "Heartbreaker" artist isn't just there to up the stakes in the competition this season. Based on the clips, she's here to give a real critique of the performances as the judges' knockout adviser, telling one contestant, "There has to be a little more punch."

Carey announced that she would be involved on The Voice as an adviser last week, saying at the time, "The sessions with the contestants, some of them have completely blown me away. It's like a humbling experience to be around all the raw talent."

There will be another big name coming to The Voice soon. John Legend will replace Hudson as a coach for the spring's 16th season of the show, it was announced in September.

"I'm thrilled to join the coaches of @NBCTheVoice. I've been a guest and mentor on the show multiple times and I'm so excited to discover talented singers and help them make the most of their gift. I hope the world is ready for #TeamJL," he wrote on social media after the news was announced.

Legend brings The Voice's first EGOT status to the coaching roles, having won at least one Emmy, Grammy, Oscar and Tony Award and become the first black man, and second-youngest person ever, to be awarded the designation earlier this year.

Season 16 of The Voice will also bring on a fifth coach for the first time ever. Country star Kelsea Ballerini will serve as the season's Comeback Stage coach, coaching the singers through a series of Comeback Battles. Two artists will come out of the battles with the help of America's votes and the winner will earn a spot on the competition's live shows that kick off in November.

The Voice airs Mondays and Tuesdays at 8 p.m. ET on NBC.

Photo credit: Instagram/Mariah Carey