The price was $1.99 for a mini-sized shake, but I received this one courtesy of Sonic.
Basically, this takes a fairly standard chocolate shake and spikes it with just a hint of jalapeno peppers. The chocolate shake is fairly standard and similar to creamy, thick chocolate milk. Unfortunately, the two flavors just don't fit well together and the end result is just a weird mash-up.
Additionally, the jalapenos are actually of the pickled variety. The pickling doesn't show up in the liquid portion of the shake; there's actually a fresh jalapeno flavor to it. But when you drink up one of the little jalapeno pieces, there's a sour and spicy burst. It's not terribly spicy but the heat is definitely there. Interestingly, the heat doesn't actually leech into the rest of the shake (although it might if left to sit long enough).
Overall, Sonic's Jalapeno Chocolate Shake is one of those things you just try out of curiosity or just to say that you did. I'm sure a few here and there will enjoy it, but, at least here, jalapeno and chocolate is a no-go for me. I suppose you can always buy one for a friend as a joke (the jalapenos aren't really apparent except as tiny shake-covered bits).
Nutritional info not available.