Ding Dongs are a snack cake made by Hostess. They are about the size and shape of a hockey puck, but Ding Dongs taste better because they are "chocolate cake with creamy filling". I like them best after they have been chilled in a freezer. Never read the nutrition information on the bottom of the box. Trust me on this.
In some areas of the US (I can vouch for Kalamazoo, MI and Atlanta, GA), the marketing geniuses at Hostess decided that "Ding Dong" wasn't a silly enough name for the discerning consumer, so they came up with the name "King Don".