Even judge Simon Cowell was predicting that Farmer's likely going to win after her jaw-dropping performance.
Flawlessly switching back between both Oscar and Petunia's voices, Farmer showed just how masterful she really is with her talent, and when the puppets broke out into a duet of The Beatles "With A Little Help From My Friends," it was almost impossible to believe what she was able to do.
"You are just hands down incredible," Mel B marveled. "You're 12 years old, you're self-taught, you were so shy, and look at you now! I've said this from the very beginning: You could win this."
Heidi Klum couldn't have agreed more, telling Farmer that she has "that special something" that makes a star, and that she "might have just won $1 million" with her amazing final act.
"The best part of doing this job is when you are there and you can say, 'I was there at the beginning of someone's career and I witnessed a star,'" Simon Cowell praised. "Tonight, again, I've just witnessed a star emerge, because that's what you are. You're special, incredible, funny, talented and I think you're going to win."
To see if the judges' predictions come true, fans will have to tune in to the America's Got Talent finals results show on Wednesday at 8 p.m. ET/PT on NBC.
For more on Farmer's beloved, hilarious performances throughout the season, check out the video below.