Vanilla Defense you mean? I've never heard of an Elephant defense.
Maybe they are trying to say our defense never forgets.
Ya thats what I meant.An elephant defense is usually a 4-3 defense with a cover-2 coverage. The only difference is that a Defensive end is usually standing up showing blitz but has the option to drop into coverage or blitz. This defensive end is known as an "elephant" end. I have no idea why, but that is what my high school called it. A lot of time a LB will come in in place of a DE to play as the elephant.
I believe the Saints brought in a 4th Linebacker in this formation bringing Marvin Mitchell in and lining up in a 3-4 but having Shanle play the Elephant in a standup DE position.
To answer your question simply, it is basically a 3-4 personell lined up as a 4-3 defense.