What is grimace shake?

The Grimace Shake is a limited-time promotional milkshake sold at McDonald's in the United States in June 2023. It was released to celebrate the fictional character Grimace's birthday. The shake is purple and flavored to resemble berries.

Following its release, a viral trend emerged on TikTok involving videos where people would pretend to try the Grimace Shake and then dramatically collapse or find themselves in strange or dangerous situations, often covered in the purple shake. These videos are intentionally absurd and played on the novelty of the shake's color and the perceived strangeness of its flavor.