Combining those flavors isn't as crazy as it might seem. If you ever have a chance to sample an Elvis Presley -- a peanut butter and bacon sandwich -- we'd urge you to seize the opportunity. And believe it or not, this isn't the first time bacon has made an appearance in a national chain's ice cream shake: For its annual "baconalia" event, Denny's offers a maple bacon milkshake.
Sonic, then, is simply building on the works of these bacon pioneers.
The result, as you might imagine, is tremendously unhealthy. The smallest size available size weighs in at 700 calories, more than you'll find in a Big Mac. The largest size packs an incredible 1,720 calories, with 118 grams of fat and 128 grams of sugar. It also boasts 55 grams of saturated fat, which is 275% of the recommended daily value.
So if you're looking to get in shape for summer, you'll probably want to steer clear of this one. But if you want to sample the cutting edge of unhealthy fast food, you can get it for half price every day after 8 p.m., along with the 24 other shakes on the Sonic menu.
Matt Brownell is the consumer and retail reporter for DailyFinance. You can reach him at Matt.Brownell@teamaol.com, and follow him on Twitter at @Brownellorama.