Duff Energy Drink is a novelty energy drink that is based on the Homer Simpson's favorite beer in the cartoon series The Simpsons. The 12 fl oz can has the exact same design as the TV show - but it is not beer! The drink reportedly has an orange flavor.
On the left is Duff (American Pale Ale, 4.8% ABV), the standard issue Duff, an American Pale Ale. It's light and crisp, but more hop-forward than a standard American beer.