It's soon to be Shamrock Shake season. McDonald's Shamrock Shake, a milkshake made with vanilla soft-serve ice cream, artificially-flavored minty green syrup and whipped topping, will return to restaurants on Monday,

On Tuesday, one day shy of six weeks before St. Paddy's Day, McDonald's is bringing back its finest creation, the Shamrock Shake.

Uncle O'Grimacey, Grimace’s Irish green uncle, is back at McDonald’s after 40 years to promote the return of the Shamrock Shake. Here's everything we know.