Tyler Perry's Boo! A Madea Halloween is chock-full of surprises, but perhaps the biggest shock at the Los Angeles premiere on Monday was a special drop-in from none other than Oprah Winfrey.

"I laughed my a** off!" Winfrey gushed to ET's Denny Directo. "Gayle [King] and I watched together, and I was literally falling out of my seat! Wait for the 'help me, Jesus' scene."

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Winfrey also got a big kick out of a reference to her iconic role in The Color Purple that is hidden in the movie.

"All of it's good," Winfrey said.

Perry reprises his role as Madea in the upcoming holiday film, in which the saucy, elderly southerner faces off against killer clowns and runaway zombies.

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"It's going to be insane," Perry said of the comedy. "I just can't wait for the audience to see it this weekend. It's going to be great."

And no one was more appreciative to have Winfrey on the black carpet than him.

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"It's awesome," Perry admitted. "Oprah's just been amazing all these years and to have that support is really great."

Boo! A Madea Halloween opens Oct. 21.