NEW YORK ( TheStreet) -- The battle for dollars in the brutally competitive fast-food business is heating up this summer, as exemplified by the arrival of several over-the-top new products.

Many of the new menu items are mashups of two or more foods that are typically sold on their own. Poof, a product that seems drawn up by a mad scientist is born. 

Importantly for fast food joints, the bizarre new products usually sell at premium prices and get people chattering about them on social media. The downside? They are often caloric bombs that hit the waistline hard at a time when fast food chains are under fire for their unhealthy menus.

One example of the fast food mashup was drive-in restaurant Sonic's (SONC)  chocolate jalapeño shake that it introduced in the summer 2014. Available for a limited time, it was a vanilla ice cream milkshake with chocolate syrup and real jalapeño slices.

This summer, Sonic has taken its mashup intensity down a notch, unveiling a croissant hot dog ahead of the July 4 holiday weekend. The product, as the name implies, uses a buttery, flaky croissant that could easily be eaten all by itself and wraps it around a hot dog.

But not every fast-food player is convinced of the need to create mashups to spur sales and create social media buzz. A spokeswoman at McDonald's (MCD) - Get Report said the burger giant "has no such menu item in the works." Similarly a Wendy's (WEN) - Get Report spokesman replied, "Not that I am aware of" when asked via email if the company was testing any unusual combinations.

At donut maker Krispy Kreme (KKD) , a spokesperson said, "I'm not aware of us testing any mashups -- of course, you periodically get someone making a Krispy Kreme cheeseburger or hot dog to sell at a county fair or some other event, but those are not Krispy Kreme approved or endorsed."

Nevertheless, some chains have clearly embraced the trend. TheStreet takes a look at three of the hottest fast-food mashups appearing on menus this summer, ranked from fewest calories to the most.

Image placeholder title

1. Pizza Hut Hot Dog Bites Pizza

The concept: 28 hot dog bites baked into a pretzel crust of a large one-topping pizza

Calories: 400 per slice

Launch date: June 2015

Price: $11.99

Price for a large Pizza Hut cheese pizza: $8 to $10

Pizza Hut's Hot Dog Bites pizza has already received tons of media attention and chatter on social media since it was first announced in early June. Yum! Brands (YUM) - Get Report, which owns Pizza Hut, is relying on the zany new pizza to help revive flagging sales. Pizza Hut, which represents roughly 60% of Yum's 13,000 plus total units, delivered a 1% same-restaurant sales decline in this year's first quarter, while same-store sales last year overall fell 3%.

Image placeholder title

2. Burger King Red Velvet Oreo Shake

The concept: Red cream cheese and chocolate-flavored shake blended with Oreo cookie crumbles

Calories: 450 (small)

Launch date: May 2015

Price: $2.59

Price for a small regular Burger King shake: $2.39 to $2.59

Red velvet has become an increasingly popular food in recent years, with packaged-food giant Nabisco releasing red velvet Oreo cookies, made with red cookies and cream cheese filling, in February ahead of Valentine's Day. Burger King's creation doesn't use the red velvet-flavored Oreos, but instead crumbles normal Oreo cookies on top of whipped cream.

Image placeholder title

3. Carl's Jr. 1/2 lb Most American Thickburger

The concept: Beef patty and American cheese, topped with a split hotdog and potato chips

Calories: 1,190

Launch date: May 2015

Price: $5.79 to $6.79

Price for a 1/2lb Carl's Jr. cheeseburger: $5.49

"We have often looked at meat as a condiment," said a spokesman for CKE Restaurants, which owns chains Hardees and Carl's Jr., in an interview at the International Franchise Expo on June 18.  In the case of the Most American Thickburger, the hot dog certainly takes on the roll of a condiment -- it's placed on the top of the sandwich, a spot typically reserved for mustard or ketchup.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.