It’s time to toast fast-food’s most iconic purple… whatever he is.

McDonald’s is celebrating the birthday of its classic mascot Grimace with a new menu item, according to a June 6 press release. Beginning June 12, customers can enjoy the Grimace Shake, a creamy lavender treat named for the nostalgic character. While the chain hasn’t announced the flavor of the new beverage, TODAY reports that it tastes like a classic vanilla shake with a hint of berries.

“Grimace’s birthday is all about paying homage to the amazing, fun moments we all share,” says Tariq Hassan, McDonald’s USA chief marketing and customer experience officer in the release. “We’re excited to put a modern spin on these memories to continue to drive McDonald’s relevance with a new generation.”

For those who are behind on their Grimace lore, the ambiguous furry creature has represented the McDonald’s brand for 50 years. Canonically, he was born on Grimace Island, and can typically be seen sipping milkshakes and hanging out with best friend and head mascot Ronald McDonald. The character debuted in marketing campaigns in 1972 as a four-armed “Evil Grimace,” according to People.

“Our timeless bestie has become a fan-favorite known for his signature fuzzy purple look, friendly and playful personality, love for shakes, and of course – ambiguous nature,” the brand says in the release. “What exactly is Grimace? Perhaps we’ll never know.”

The Grimace Shake will soon be available exclusively in the Grimace Birthday Meal, which includes a Big Mac or 10-piece nuggets and a side of fries.