Surreal reference to the super cult John Carpenter movie "They live". Sunglasses, aliens and attitude… And as Nada said: "I am here to chew bubblegum and kick ass… and I'm all out of bubblegum…".
"I have come here to chew bubblegum and kick ass...and I'm all out of bubblegum." -Ad libbed by Roddy "The Rod" Piper (played Nada) in "They Live" Duke Nukem subsequently put a version of the line in their game as the Duke Nukem character was loosely based on Nada from this film.