From the various flavors that have been available to the struggles of unveiling it nationwide, here's what you should know about McD's minty green shake.

Have you ever wondered what gives McDonald's iconic Shamrock Shake that distinct green color? You may not be surprised by the answer.

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 a milkshake made with vanilla soft-serve ice cream, artificially flavored minty green syrup and whipped topping. McDonald's debuted the first Shamrock Shake in 1970, and the cult classic has been returning to the menu around St. Patrick's Day each year since.

McDonald’s signature Shamrock Shake is set to return for limited time this year. The shake will be sold at participating McDonald’s restaurants nationwide starting Monday, Feb. 10. The Shamrock Shake is made with vanilla soft serve blended with McDonald’s minty Shamrock Shake syrup and topped with whipped cream.

One of the most recognizable holiday treats at McDonald's is making its return, along with one of Grimace's relatives.

The beloved Shamrock Shake is coming back to McDonald's, along with a McDonald's character no one's seen since the 1980's: Uncle O'Grimacey.

Shamrock Shakes are back at the restaurants. The Oreo Shamrock McFlurry has made a limited time return, as well. Start the day smarter. Get all the news you need in your inbox each morning. Shamrock Shakes sales do some good.