This sounds gross, but it’s got a pretty big cult following online: Pepsi just launched a new ad campaign where they’re trying to get more people to try “PILK” . . . Pepsi mixed with MILK!

They didn’t come up with the name, or the idea. It was on “Laverne & Shirley” in the ’70s, because it was Penny Marshall’s favorite drink. Fans have compared the taste to a “Coke float,” where you pour soda over vanilla ice cream.

The idea also went viral a few years ago. And it’s similar to the whole “dirty soda” trend, where you mix in cream and flavored syrups.

Now Pepsi is trying to get Pilk trending for the holidays. They’re doing a sweepstakes, and an ad campaign with Lindsay Lohan.

If you post a photo or video of yourself enjoying some “Pilk and cookies” between now and Christmas, you’ll be entered into a drawing to win holiday cash. 25 people will get $1,000 each. You just have to tag Pepsi on TikTok, Instagram, or Twitter, with the hashtag “PilkAndCookies”.

They also came up with some recipes. Like mixing in flavored coffee creamer, or using Wild Cherry Pepsi instead of regular.