Can someone explain to me Who Dat? in relation to the Saints?

“Who Dat” became part of a chant for fans cheering on their favorite team. It has been debated exactly where it started, but some claim it began with Southern University fans either in the late 1960s or early 1970s and went “Who dat say dey gonna beat dem Jags” – Southern University being nicknamed the Jaguars.[3] Another claim is that around the same time it began at St. Augustine High School, a historically African-American all boys Catholic high school in New Orleans, and then spread to the New Orleans Public Schools. Another claim is that the cheer originated at Patterson High School in Patterson, Louisiana (home of Saints running back Dalton Hilliard).[2] In the late 1970s fans at Alcorn State University and Louisiana State University picked up on the cheer.[4] By 1983, the New Orleans Saints organization officially adopted it during the tenure of coach Bum Phillips, and Aaron Neville (along with local musicians Sal and Steve Monistere and Carlo Nuccio) recorded a version of “When the Saints Go Marching In” that incorporated the chant (performed by a group of Saints players) that became a major local hit, due in part to the support of sportscaster Ron Swoboda and the fact that Saints fans had been using the chant already.[2] Meanwhile, in about 1981 Cincinnati Bengals fans and players had started with their similar “Who Dey” cheer.[5]

After the Saints won the NFC Championship Game on January 24, 2010, against the Minnesota Vikings in the Superdome, fans from all across New Orleans, including fans who were exiting the game, started a Mardi Gras-style “Who Dat” on Bourbon Street with modified lyrics, chanting, “Who Dat, Who Dat, Who Dat in the Super Bowl!” in reference to the Saints advancing to the Super Bowl for the first time ever in their 43-year history.

-Wikipedia

according to Wikipedia also!

In recent years the phrase “Who Dat Nation” has become a popular term for the community of Saints fans.[8][9][10] According to Bobby Hebert, formerly a Saints quarterback and currently a sports commentator in New Orleans, the term “Who Dat Nation” originated after a highly anticipated 2006 game between the Saints and the favored Dallas Cowboys, which the Saints won; after the game, listeners from a wide geographic range called in to Hebert’s radio show on WWL (AM), and Hebert commented, “Man, there’s a whole Who Dat Nation out there.”[11]

NPR is where I learned about Who Dat.

I’m a Louisiana native and life long Saints fan. The chant is Who Dat say da gonna beat dem Saints? Who Dat? It’s a chant that has been used most of my life. We were so excited to get a winning season way back in the early eighties. The chant became a battle cry way back then. It means Who is that who says they are going to beat our Saints? French was mainly spoken in south Louisiana even when my father was a child. They learned English upon hearing it when they went to school. They were literally beaten for speaking French at school. They learned a broken form of English where this is dis and da is they and dat is dat. Some of our grandparents never learned English.

Just to add to the above, recently the NFL tried to keep people from marketing the phrase, however it is so embedded in the culture that their efforts failed miserably….

http://www.wwltv.com/news/Trademark-attorney-Who-Dat-controversy-is-one-for-federal-courts-83075857.html

And my SIL, who is a “Yat” (a native New Orleanian) says about the game:

“Dem colts dint hole a cannel to dem saints!”

@Darwin : I know dats true! We went to the victory parade last night. It was awesome.