The reign of the simple cheeseburger is over. From Taco Bell‘s Quesarito to Burger King‘s Mac N’Cheetos, these junk Food mashups are changing the face of fast food.

When I was a kid, cheese-stuffed pizza crust was about as innovative as fast food got. These days? You’re hard pressed to find even a simple cheeseburger on fast food menu signs among overblown images of novelty Food Mashup items.

Though mashups are new, fast food has been using limited time-only menu items to drive up interest for years.

McDonald’s McRib was first introduced in 1981. Surprisingly, at least to those of us who are familiar with the current food bro feeding frenzy and social media furor surrounding the McRib’s seasonal availability, it initially had poor sales and was removed from the menu. It was reintroduced in 1989, then taken off again in 2005. But the real craze over the McRib has been in the years since, where its (usually autumnal) arrival causes people to suddenly go crazy over a fast food restructured pork patty.

KFC‘s Double Down also caused a huge stir when it was first released. The Double Down is a sandwich that replaces buns with fried chicken filets. It’s filled with bacon, two kinds of melted cheese and Colonel‘s secret sauce, making it one of the most notable fast food trends to make a name for itself by being, well, kind of gross (or at the very least, potentially deadly to those with any sort of heart problem).

The Double Down was introduced in 2010 as a limited time-only menu item, but it was so popular that it was kept around much longer than planned, making $50 million in its first 3 months on the menu. It has since been revived several times as a limited time-only item.

But fast food has taken things even farther, and these days, food mashups are the menu items driving customers to the drive-thru, likely because of the press coverage and social media shareability of such items.

The poster child of this trend seems to be the Doritos Locos Taco, borne of a partnership between Taco Bell and Frito-Lay and introduced in 2012. The Doritos Locos tacos replaces the standard Taco Bell crunchy corn shell with a shell seasoned like Nacho Cheese Doritos.

It seems like a simple ingredient swap, but it’s one that’s made a ton of money for Taco Bell. In the first year alone, the chain sold more than a billion Doritos Locos Tacos, and it’s estimated that 15,000 employees were hired to deal with the extra workload. The Doritos Locos taco now comes in three flavors and is a permanent fixture on Taco Bell’s menu.

After the “DLT,” Taco Bell has experimented with a breakfast food mashup, the waffle taco, along with the new Quesarito, which fuses quesadilla and burrito into one cheesy, gooey, and admittedly delicious mess.

This type of innovation has been a great motivator for Taco Bell’s competitors. After a surprising slump in sales, McDonald’s saw a turn-around in its 2016 first quarter revenues after introducing all-day breakfast, which was a big move for the relatively conservative chain.

Now, Burger King wants to get in on the fun – it’s started serving grilled hot dogs, and earlier this year added Chicken Fries Rings to the menu (a sort of food mashup inception featuring their french fry-shaped chicken fingers further mutated into an onion ring shape). Burger King also saw a rise in sales in Spring of 2016, which may have spawned its next release.

If anything encapsulates the freaky food mashup trend, it’s this: a Cheetos-encrusted, molten blob of macaroni and cheese, deep-fried until crispy. Mac N’Cheetos were released in June of 2016 to great fanfare. They may sound like something a vegetable-hating toddler would invent, but given the proven success of frankenfood trends, it’s no wonder the suits at Burger King are starting to think so far out of the box.

So, fans of the simple chicken nugget and burger, beware. The next time you order your favorite fast food item there’s a good chance you’ll have to unwrap it from a soft pretzel or dislodge it from a Frito-Lay crust first.

"These Weird Fast-Food Mashups Are Becoming the Norm" originally published on The Menuism Dining Blog.