McDonald's Grimace Shake: How a Purple Birthday Drink Became a TikTok Horror Trend

In June 2023, a TikTok user posted a video. He wished Grimace, the purple McDonald’s character, a happy birthday, took a sip of the new Grimace Shake, and then the video cut to a scene of him lying motionless on the floor, purple shake spilled around him, as if in a horror film.

Within days, thousands of people were copying the format. The “Grimace Shake trend” became one of the most viral moments of the summer.

McDonald’s had not planned it. But it benefited enormously.

The Context

Grimace is one of McDonald’s oldest characters. He first appeared in the 1970s as part of the McDonaldland universe, a purple, round creature who was a friend of Ronald McDonald. Over time, McDonald’s used its characters less in advertising, but Grimace remained familiar to people who grew up in the 1980s and 1990s.

In 2023, McDonald’s decided to celebrate Grimace’s “birthday” with a limited-time Grimace Birthday Meal, which included a berry-flavoured purple shake. The meal launched in the US on June 12. It was supported by social media posts, a Grimace birthday video game and nostalgic marketing aimed at millennials and Gen Z.

The Campaign

The official campaign was playful and nostalgic. McDonald’s released images of Grimace celebrating his birthday and encouraged fans to wish him happy birthday online.

The internet took the idea in a different direction. The first viral video, posted by TikTok creator Austin Frazier, followed a simple format: a cheerful “Happy birthday, Grimace” and a sip of the shake, followed by a scene of the person apparently collapsed, often in a strange or dramatic setting, with purple shake splattered around them. The joke was that the shake was so mysterious that it had terrible effects.

Others copied and escalated the format. People filmed themselves apparently collapsed in bathtubs, in cars, on playgrounds and in woods. Some videos used horror film music, fake news reports or crime-scene tape. The trend became a showcase of creativity and dark humour.

McDonald’s faced a choice. The trend was about people pretending to die after drinking its product. Many brands might have tried to stop it or distance themselves. Instead, McDonald’s acknowledged it lightly. The official McDonald’s account posted an image of Grimace with the caption “meee pretending i don’t see the grimace shake trend.” That response was widely shared and praised as a smart, relaxed way to engage.

The Grimace Birthday Meal remained available for a limited time, and demand was high. Many people bought the shake specifically to make their own video.

Why It Worked

The product was visual. The shake was bright purple, which made it easy to spot in videos. It stood out on camera.

The format was easy to copy. Anyone with a phone and a shake could join in. The simple structure, birthday wish, sip, dramatic cut, encouraged creativity.

Nostalgia and humour combined. Grimace was familiar and slightly odd. Turning a childhood character into the star of horror clips was funny because it was so unexpected.

McDonald’s didn’t overreact. The brand recognised that the trend was a joke and responded with a joke. Trying to control it would have killed it.

Scarcity helped. Because the meal was only available for a short time, people rushed to buy the shake before it disappeared.

The Results

Videos tagged with the Grimace Shake trend were viewed billions of times on TikTok. News and entertainment outlets covered the trend widely.

McDonald’s reported US same-store sales growth of 10.3% in the second quarter of 2023. CEO Chris Kempczinski told investors that the Grimace Birthday Meal was one of the contributors to that growth.

The trend also showed how younger consumers interact with brands. They did not simply share the official content. They remixed it, often in surprising ways, and made it their own.

McDonald’s continued to lean into nostalgia and fan culture in later campaigns, including limited-time items and collaborations tied to its characters and history.

The episode also raised questions about how much credit a brand deserves for a trend it did not create. McDonald’s did not invent the horror format; its customers did. But the company created the conditions for it: a strange, nostalgic character, a vivid product, a limited window and a social media team confident enough to play along. Marketers increasingly talk about designing for remix, creating products and campaigns that give audiences room to make their own content.

The Lesson for Today’s Marketers

You cannot control how the internet uses your brand. But you can control how you respond. McDonald’s showed that a light, confident response can turn an unexpected trend into a win.

Visual, limited products are made for social media. A distinctive colour and short availability gave people a reason to buy and film.

And nostalgia is powerful, especially when fans are allowed to reinterpret it. Grimace succeeded because people could play with him, not just admire him.