With the holiday season in full swing, Purchase, N.Y.-based PepsiCo unveiled its new holiday campaign featuring Lindsay Lohan and Santa inviting fans to try a surprising and naughty new twist on an old tradition with the introduction of Pilk and Cookies.

For those new to Pilk, it’s a drink that combines the crispness of Pepsi with the subtly sweet and creamy taste of milk, traditionally topped with creamer, and it pairs perfectly with cookies, the company says. Known in pop culture as a "dirty soda," this trending combination has grown over several decades and has recently gained viral fame on TikTok, it notes.

"Combining Pepsi and milk has long been a secret hack among Pepsi fans,” said Todd Kaplan, chief marketing officer at Pepsi, in a statement. “Now with the rise of the 'dirty soda' trend on TikTok and throughout the country, we thought Pilk and Cookies would be a great way to unapologetically celebrate the holidays with a new and delicious way to enjoy Pepsi this season.”

Starting today through Dec. 25, Pepsi is inviting fans to join the naughty list with the #PilkandCookies Holiday Challenge, giving 25 consumers the chance to win cash for their holiday gifts. To enter, fans must follow @Pepsi on Instagram, Twitter or TikTok and share a photo or video of their dirty, delicious Pilk and Cookies treat with the #PilkandCookies #Sweepstakes hashtag.

To kick off the challenge and announce this new tradition, Pepsi teamed up with two stars of the holidays — Lindsay Lohan and Santa, it says. Lohan, fresh off her holiday film, Netflix's "Falling for Christmas," and recently released rendition of "Jingle Bell Rock"can be seen enjoying Pilk and Cookies in a short clip with Pepsi and Santa on the brand's YouTube.  

"Partnering with Pepsi to announce Pilk and Cookies has been an incredible experience," Lohan said in a statement. "As someone who loves the holiday season and embracing new traditions, I was thrilled to have a little bit of fun with Pepsi and their take on the dirty soda. For people learning about Pilk for the first time, I won't lie to you when I say I was a bit skeptical when I first heard of this pairing, but after my first sip I was amazed at how delicious it was, so I'm very excited for the rest of the world to try it."