Grimace and Uncle O’Grimacey are welcoming the Shamrock Shake back to restaurants nationwide on Monday, Feb. 10

McDonald’s is bringing back its beloved Shamrock Shake with the help of an old friend. The minty green milkshake will return to restaurants on Monday, Feb. 10 — and the chain’s Uncle O’Grimacey character is returning after a decades-long hiatus to help kick off the annual “Shamrock Season.”

The Shamrock Shake is back at McDonald’s—and so is Grimace’s Irish uncle, Uncle O’Grimacey. And yes, there’s already merchandise available. Nostalgia is an easy way to draw eyes to whatever product you’re pitching to consumers,