This issue is a variant of Batman / Superman (DC, 2013 series) #9. There exist further variants.
1:25 variant cover. Credits for the cover list Tom Richmond as the artist for the Mad Magazine variant cover, but this is the Robot Chicken variant cover. The Mad Magazine cover is on Batman / Superman #10.
Story continued from Worlds' Finest (DC, 2012 series) #20 and story continues in Worlds' Finest (DC, 2012 series) #21.