The buzz around the “Toy Story 5” premiere in Hollywood turned into a full-blown pop culture earthquake when Taylor Swift made a surprise appearance on June 9, catching even the film’s biggest stars completely off guard.

How Taylor Swift Pulled Off the Secret Premiere Appearance

According to Michigan native Tim Allen, who spoke with Jimmy Kimmel, the secrecy surrounding Swift’s involvement was so tight that even he and co-star Tom Hanks had no idea “TS” meant Taylor Swift instead of “Toy Story.”

READ MORE: Stephen Colbert Returns to Late Night in Michigan, Sparks CBS Backlash

USA Today reports that Swift skipped the traditional red carpet entirely, slipping into the Dolby Theatre through a secured backstage entrance. There, she met cast members privately, including Hanks, who returns as Woody. In a lighthearted moment, Swift reportedly brought an original VHS copy of the first “Toy Story” film for Hanks to sign, setting the tone for a nostalgic night.

Michigan’s Tim Allen Caught Off Guard by Taylor Swift

Allen, a Michigan native with deep roots in Flint’s entertainment legacy, said the surprise was one of the most tightly guarded secrets he’s seen in decades of Hollywood work. Cast members including Joan Cusack were also in attendance as Pixar’s newest installment built toward its big debut.

Taylor Swift Turns 'Toy Story' Premiere Into Concert Event

After the screening at the Dolby Theatre, the night took a dramatic turn. Swift appeared onstage at a piano to a roaring crowd, performing an original song titled “I Knew It, I Knew You,” co-written with Jack Antonoff for the Pixar sequel.

Swift told the audience she grew up with the franchise and called “Toy Story 5” her personal favorite in the series.

Randy Newman Joins Taylor Swift for Nostalgia Moment

The surprise didn’t stop there. Legendary composer Randy Newman joined Swift on stage for an emotional duet of “You’ve Got a Friend in Me,” sending the crowd into full nostalgia overload.

READ MORE: Jimmy Fallon Brings 'The Tonight Show' to Detroit

The audience also included new cast additions like Conan O'Brien and Greta Lee, alongside returning franchise voices.

What began as a traditional red carpet premiere quickly transformed into a hybrid concert, fan celebration, and Hollywood spectacle rolled into one unforgettable night.

Toys From the '70s and '80s That Could Have Killed Us

LOOK: How Many of These Classic '80s Summer Toys Do You Remember?

Whether you slipped and slid or jarted better than anyone, the toys of your childhood summers were everything. Here's a look at just some of the classics.

Gallery Credit: Stephen Lenz