A socially deficient, morally reprehensible, or intellectually inferior person. The term implies a variety of negative qualities, specifically unwarranted arrogance and levels of inadequacy that exceed classification as a Douche, a Douchebag, a Douche Nozzle, or an Über-scrote.
Jack: "No, Dick has attained such unprecedented levels of douchebaggery, that he's actually a Douche Gargler."
Jill: "Yep. That's Dick all right. A total Douche Gargler."