Blake Lively Reunites with 'Sisterhood of the Traveling Pants' Co-Star Amber Tamblyn for Halloween!

Blake Lively and Amber Tamblyn are celebrating Halloween together!

The longtime friends and former Sisterhood of the Traveling Pants co-stars had a mini reunion in honor of Halloween.

Click inside to watch the video!

On Sunday (October 31), Amber took to Instagram to share a video, where Blake made a surprise and silly cameo.

“Look what I got in the mail!” Amber says in the video while unboxing a gift from Blake‘s drink mixer brand Betty Buzz.

“Ooh, Betty Buzz! It’s so beautiful,” Amber continued. “Look inside, it’s so pretty! So, this was the biggest package I’ve ever received in the mail. There was like a whole package, and then there was a person inside of the package. It was really weird.”

She then panned the camera up to reveal Blake standing behind her, wearing a brunette wig with a red, sequined cloth wrapped around her.

“@BettyBuzz really has outdone itself on marketing by sending me this gorgeous box of tasty refreshments and a life-size Blake Lively Halloween mannequin for my front yard,” Amber captioned the post.

Blake and Amber starred alongside America Ferrera and Alexis Bledel in 2005′s The Sisterhood of the Traveling Pants and the 2008 sequel.

Since then, the four ladies have remained super close.

Last year, Amber revealed which actress gets the “most lit” when they all hang out!