Kellogg's "Icee" cereal. Tempted to buy a pallet and sell them to collectors on eBay. Clever idea -- they taste right, feel cool in your mouth, and you don't have to seek out a soda fountain. (Your first guess, 7-11, would be incorrect.) Sadly, they were on clearance in just a few months.
The box uses the mascot from different design eras; the one on the front looks very 1990s. In fact the whole package, including the text, seems to scream "Gen-X Nostalgia."