Wis-Pak Pepsi’s original competition to Dr. Pepper as Pepsi pulled Dr. Slice, its only similar product, from the market. In some markets, Mr. Green and then Cheerwine temporarily replaced this flavor profile. It's not original Mr Pibb, but the closest thing you'll ever taste to it, we guarantee! Repeat -- It tastes like Pre 2002 pIBB!!! It's not Xtra bad!
As of Fall 2016, this product has been discontinued by the manufacturer and rereleased as Doc X. Still tastes the same but now with more caffeine, touted as an energy drink (but not quite). The caffeine addition does slightly change the flavor of the new concoction.
Doc X is available, click the Regular tab to find it.