Did somebody say McDonald's? McDonald's is celebrating a big birthday this year with a special meal and milkshake devoted to the one and only purple guy, Grimace. 

I know you might be thinking, wait, who's Grimace? The purple guy, right?  Yes, you're right.  But what is Grimace?  That's still undecided. Seriously, you can Google 'what is Grimace' and find long articles wondering the same thing, ending up inconclusive.  Though there's a big theory that he's a giant taste bud.

To celebrate his birthday, McDonald's launched a new purple milkshake, but there's a twist. 

You can't just order the milkshake.

How Do You Order the McDonald's Grimace Milkshake?

You have to choose one of the two Grimace Birthday Meals in order to score the shake.

Smart marketing, McDonald's, smart marketing.

Your Grimace meal choices are: a Big Mac and Fries or 10 piece McNuggets and fries.

MORE: Rockford Area Best BBQ Spots

When you order one of those combos, then you can have the Grimace shake.

What Does the McDonald's Grimace Shake Taste Like?

According to NBC New York, it's actually more vanilla flavored than another else, it's described as their vanilla soft serve and berry flavors.

The best comment from the NBC team is that one of their kids said it tasted like grape Claritin.

I think 'buy a Grimace Birthday Meal' is on my weekend to-do list.

LOOK: 15 Discontinued McDonald's Menu Items

Top 11 Places To Cure a Chicken Tender Craving in Northern Illinois

Looking for some great chicken tenders? Here are 11 of the top spots in Illinois to find them.

More From 97 ZOK