Despite the fact that the Shamrock Shake is essentially a McDonald's vanilla shake with green food coloring and mint flavoring, McDonald's fans anticipate its return every year. However, if you know the correct verbiage, you might just be able to get your hands on a secret menu milkshake that could replace the Shamrock Shake as the object of your desire.

That secret item's name is the “McDonald's McLeprechaun Shake,” and you only have a chance to snag it while the Shamrock Shake is in circulation. It's essentially a half-and-half concoction, blending the Shamrock Shake and a standard McDonald's chocolate shake together.

To get this delicious concoction, you'll need to ask for it by name and hope you luck out with a cooperative McDonald's employee that is willing to make it for you. Additionally, as with the standard Shamrock Shake, the availability of this off-menu treat will depend on supply.