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.”

He hasn't gone away, you know - after becoming an Internet legend, Uncle O'Grimacey is returning for McDonald's Shamrock Shake charity campaign. Was Uncle O'Grimacey in the IRA?!