Major fast food chains in general tend to offer many quirky variations of their flagship products. One reason is catering to local tastes without diluting the brand too much while another is providing an additional excuse to jack up the price compared to the old favorites they've been serving for decades. Experimentation is common in the F&B industry but fast food is inherently open to 'hybridization' as some traits have to be maintained.
Fast food chain Wendy's has introduced a sandwich called "The Baconator", apparently combining the deliciousness of bacon with the deadliness of the Terminator. Or possibly vice-versa. Either way, you die happy.
Yum! Brands is known for combining its three flagship fast food brands, KFC, Taco Bell and Pizza Hut. KFC/Taco Bell are the most common, but Taco Bell/Pizza Hut (which even has a song written about it) and KFC/Pizza Hut are not unheard of. There's also the very rare KFC/Taco Bell/Pizza Hut, sometimes affectionately referred to as the "KenTacoHut".
Long John Silver's and A&W had the same parent company in the 1990s (Yorkshire Global), which led to the occasional co-brand. Both also began co-branding with KFC in the 1990s, although they were under different owners at the time.
After Tricon Global bought out Yorkshire to become Yum! Brands, the company began co-branding Long John Silver's with Taco Bell. Fish tacos made with deep-fried fish?
And on top of that, some Pizza Huts have Wing Street in them.
There's also Orange Julius and Dairy Queen. Queen Julius? And if you're lucky, it might have a Karmelkorn in it as well.
The infamous Baskin Robbins/Dunkin' Donuts combo. Because, you know, what's a donut without an ice cream sundae to wash it down? ◊ And in some cases they're combined with Togo's Subs, which the company calls a "trombo".
Likewise, Canadian donut chain Tim Hortons has combined with Wendy's (which used to be under the same ownership) and Cold Stone Creamery, both in Canada and the US.
Yogurt chain TCBY went on a major co-branding spree in the 2000s, usually with Subway and Blimpie.
While Blimpie itself launched three other concepts (Smoothie Island, Pasta Central and Maui Tacos) which were often co-branded.
Mrs. Field's cookie shops often have Pretzel Time in them. Some used to have the aforementioned TCBY.
Midwestern taco chain Taco John's also had a few locations that were co-branded with Steak Escape.
Half the items on Burger King's menu, such the "Tendercrisp," a chicken sandwich with bacon on it. They seem to be on a quest to produce as many heart attack-inducing sandwiches with cool names as possible.
In the UK the Tendercrisps are actually the Healthiest Chicken-Product that Burger King has to offer, being of a Higher-Quality Chicken Breast than the Royales or Bites, they then add the usual Filler (Salad, Mayo, etc), with no Bacon whatsoever.
They lose to the Double Down sandwich from KFC, which uses three animals at once. Fried chicken, bacon, and some of the most processed cheese you've ever seen.
There's so much Meat that there's no room left for the BUN! It uses Chicken Breasts INSTEAD of a Bun!!
The Luther burger. Oh God (yes) the Luther burger. A half-pound beef patty smothered with cheese and onions in between two grilled Krispy Kreme donuts. If that doesn't send you into insulin shock just reading about it...
It probably contributed greatly to the death of the man it's named after, Philadelphia Soul legend Luther Vandross.
Elvis Presley had a thing for grilled peanut-butter-and-banana sandwiches, apparently. He also liked the Monte Cristo sandwich: a ham-and-cheese sandwich that was battered, deep-fried, and topped with jam and powdered sugar.
The fool's gold loaf. Take one hollowed-out loaf of lightly toasted Italian bread, then add one whole jar of creamy peanut butter, one whole jar of grape jelly, and one pound of warm crispy bacon. Somewhat unsurprisingly, Elvis reputedly had a fondness for these... Or rather, more than just a fondness. He flew out to Denver from Tennessee (that's two hours each way) just to eat a few of these. That's right—a few. He ate at least 4 of them over the course of three hours...then flew back to Memphis. He never even left the airport.
And, just to be classy, he washed them down with Perrier sparkling water and Dom Perignon.
According to Gunther Toody's the King also had a penchant for french fries, topped with sausage gravy and shredded cheddar.
Well, there's nothing wrong with that. That's just a variation of poutine.
That's not dissimilar to the signature dish of Springfield, IL, the horseshoe, which is some kind of meat (usually hamburger) on Texas toast, smothered in cheese fries.
Similarly, "Weird Al" Yankovic likes Twinkie wiener sandwiches with Easy Cheese and dipped in milk. He's even seen eating one in UHF.
He also showed us how to make other food hybrids in every episode of The Weird Al Show.
Carl's Jr. for a short time had a 1/3-pound burger topped with pastrami. That's right, they used meat as a condiment. The executive vice president of marketing said, "It combines two great tastes - a delicious Carl's Jr. burger and a classic, steaming hot pastrami sandwich - into one awesome mutant burger."
Unfortunately, they were late to the party, since several local chains in Utah have been serving pastrami burgers since the 70s.
Pastrami burgers are quite often seen in kosher restaurants as a substitute for bacon burgers. They're better than the not-really-cheeseburgers with the fake cheeze-like-substance on them (cheese is a dairy product; mixing dairy and meat is forbidden by kashrut).
Carl's Jr. has also marketed the Philly cheesesteak burger (a burger topped with chopped steak and cheese, which could be had in a triple burger variant - yes, that's three patties plus chopped steak, for those playing along at home), and the breakfast burger (a burger topped with a fried egg and hash browns) has become a staple on its menu. Suffice to say, Carl's Jr. loves this trope.
And their latest creation, the prime rib burger, a burger topped with horseradish sauce and sliced prime rib.
Since Carl Karcher bought out the Green Burrito franchise, an awful lot of Carl's Jr/Green Burrito locations have been popping up all over the west coast, and most Carl's Jr. locations at least offer the Green Burrito taco salad. Which is awesome.
It's only awesome until you've prepared one, or seen that nasty refried-bean stuff by itself. Ugh, instant inedibileness.
The whole concept of the taco salad in general is a classic example of this trope.
Turducken, chicken inside duck inside turkey, it is the Russian doll of both food and birds.
There is also the fabled osturducken: A chicken inside a duck inside a turkey inside an ostrich. And apparently in Georgia (the central Asian country, not the U.S. state; but there's so much going on in America, you never know) you can get a chicken inside a duck inside a turkey inside a lamb inside an ox. This blog post talks more about the practice of stuffing dead animals inside each other.
There is also "Baturducken," in which each stage of the turducken is wrapped in bacon. Not bats.
The ducken from Red vs. Blue beats that. You start with a hummingbird, stuff that in a sparrow, stuff that in a chicken, stuff that in a duck, then a turkey, then a BIGGER turkey, stuff that in a penguin, stuff that in a peacock, then an eagle, shove that in an albatross, then an emu, next comes an ostrich, then a leopard, (For presentational purposes) put all that into a pterodactyl, and then stuff it into a Boeing 747.
That almost beats the Nodwickversion: a hedgehog inside a dire boar, inside a bulette, inside a purple worm, inside a tarrasque (And at some point, one of the two latter apparently ate Nodwick). (Apart from the hedgehog, these are Dungeons & Dragons monsters of increasing size and ferocity. None of them are recorded as being appetizing, though, although the Monster Manual is bereft of nutrition facts and deliciousness scores.)
Yet another version, claimed to be served at feasts for Arab royalty involves fish stuffed with rice stuffed into chickens which are then stuffed into a sheep with are stuffed into a camel.
A French cookbook from the 19th century attests to what may be the most elaborate nested-bird dish ever conceived - a bustard stuffed with a turkey, a goose, a pheasant, a chicken, a duck, a guinea fowl, a teal, a woodcock, a partridge, a plover, a lapwing, a quail, a thrush, a lark, an ortolan bunting and a garden warbler, the final bird stuffed with an olive in its mouth.
Gaze on the wrongness of the 100x100. Eventually someone's going to buy a whole steer and grind it.
That could feed a family for weeks.
In-N-Out Burger is famous (or infamous, depending on your definition of Food Crimes) for doing almost anything to a burger. Try the double cheeseburger with french fries on it.
And Bacon soda if you want to skip the alcohol (or add it yourself).
The Long Island Iced Tea: Vodka, Tequila, White Rum, Triple Sec, Gin, sour mix, and a splash of cola. Seven tastes that taste surprisingly mild, and gets you nice and buzzed. Numerous variations exist, including the "Romulan ale" or "AMF" which substitutes blue curacao for the triple sec, or some which add a sixth liquor, such as Chambord or Midori.
In a similar neighborhood is the Zombie, a classic tiki drink featuring a shot each of white rum, gold rum, dark rum, 151 rum, apricot brandy, and peach brandy, topped off with pineapple juice. It got its name because drinking a zombie was reputed to turn you into one, and to this day Trader Vic's limits its customers to no more than two of them.
It's not uncommon to brew beer (a stout or porter, generally) with (unsweetened) chocolate in it. Somewhat surprisingly, the result is not much different from many darker stouts and porters which don't actually contain chocolate, but taste of it nonetheless.
On a superficially similar note, though to much different effect, red wine/chocolate mashups have become popular in recent years. The chocolate isn't an ingredient in the wine itself here, though; it's mixed with ordinary red wine before being packaged for sale.
To eat all these Ninja Pirate Zombie Foodstuffs, you can always use a spork, the eating-utensil version of this trope.
The Tropicana "Tropolis", which promises to "Snackitize" drinks and "Drinkitize" snacks. Whatever that means.
Apparently, it means selling watery applesauce as something new rather than something disgusting.
One that Britons might not think is odd but which many Americans are unfamiliar with is the "chip butty", essentially a steak-fry sandwich.
Fried-potato sandwiches are absurdly common in the Arab world, as well. In the small restaurants that serve as the Arab equivalent of chip shops, it is almost impossible to tell the guy at the counter that no you do not want your fries in a sandwich, you want them in a separate box/bag.
Possibly the strangest variant of this has to be the maakouda (Moroccan potato cake) sandwich: the potatoes are boiled, then mashed, then mixed with egg and seasoning, then formed into patties which are dipped into egg again before being deep fried, then heated on a grill with cheese, egg, or both, and then smashed flat inside a warm loaf of bread. A common and delicious breakfast item across the country, although most popular in the Middle Atlas region (around Fes and Meknes).
Students pulling all-nighters (or all-weekenders) before Finals sometimes resort to brewing coffee using Jolt Cola in place of water. For when you absolutely, positively, have to finish that term paper, albeit probably in gibberish.
Beef Wellington, which legend attests was conceived upon a request from the eponymous Duke, is a similar mishmash - a beef tenderloin, topped with foie gras and mushrooms sauteed in cream and butter, and wrapped in a puff pastry.
The "Bacon Explosion". It combines Bacon. With Beef. And Bacon. When your first step is "make a bacon weave", you know you've got a winner.
The "fat sandwich", a specialty of the Grease Trucks of New Brunswick, New Jersey, combines various fried products on a sub roll, including burger patties, french fries, cheesesteak, mozzarella sticks, chicken fingers, pork roll, falafel, gyro meat, bacon, fried eggs, and various sauces, cheeses, and other toppings. That such a device would appear in New Brunswick is to be expected, seeing as it is the location of Rutgers University,note In full: Rutgers, the State University of New Jersey with its attendant drunk and otherwise-intoxicated students in need of late-night fatty meals.
The Primanti sandwich, the signature dish of the likewise-named Pittsburgh chain, combines a sandwich meat with french fries, coleslaw, tomato slices and melted cheese.
Cincinnati-style chili con carne is an adaptation of the classic stew made to the taste of the city's Greek immigrants in the 1920s, flavored heavily with allspice, cinnamon, and cocoa. It is typically served as a "three-way", "four-way", or "five-way" - over spaghetti, covered in a large mound of shredded cheddar cheese, and with onions, garlic, or beans. More exotic versions may also add sour cream, coleslaw, or a fried egg to the mix.
The Indianapolis-based Cajun/Creole restaurant chain Yat's is known for its "chili cheese étouffée."
"Yuanyang tea", a specialty of Hong Kong and Taiwan, is made of seven parts Hong Kong-style milk tea and three parts brewed coffee; HK milk tea is itself one part milk to six parts strong brewed tea. When you absolutely Must Have Caffeine (and sugar and fat), this is not a bad way to go.
David Foster Wallace is also noted to have enjoyed a beverage made by steeping several different bags of tea in brewed coffee.