The Daffy Duo is a popular animated duo consisting of Daffy Duck and Bugs Bunny. The two characters have been featured in numerous Looney Tunes cartoons since the 1940s. The term 'EFS' is an acronym for the phrase 'Enemies For Sure', which is often used to describe the relationship between the two characters. The Daffy Duo's relationship is often characterized by their constant bickering and rivalry, but they are also known to work together when needed.