<P> Who dat? is an English idiom originating from New Orleans . First generally referenced in poetry, the phrase was a common dialogue element between the performers and crowd at traveling minstrel shows in the region . Eventually, the phrase became used in US cinematic productions for two decades, including TV and movies . In World War II, the phrase became known as a source of entertainment for American soldiers . </P> <P> More recently, the phrase "Who dat?" has become a chant of team support . It is most widely used by fans of the New Orleans Saints, an American football team . The entire chant is: "Who dat? Who dat? Who dat say dey gonna beat dem Saints?" "Who dat" may also be used as a noun, describing a Saints fan . </P>

Where did the expression who dat come from