In one episode, numerous objects, including the head of Adolf Hitler, are found floating in bottles of Duff Beer as they go down the assembly line. In another, Bart and Lisa Simpson travel with their aunt to Duff Gardens, a parody of the Busch Gardens amusement park with elements from Disneyland included. There, they see the mascots of Duff Beer, the Seven Duffs: Sleazy, Queazy, Edgy, Surly, Tipsy, Remorseful, and Dizzy. Also, Bart and Lisa visit the "It's A Duff World" attraction, where they hear this song (repeated over and over and over ...).
Duff Beer for me! Duff Beer for you! I'll have a Duff, You have one too!