doppelfail 

Someone who attempts to be a doppelganger, or carbon copy of another person, and only looks like an ass doing it. Often unpleasantly reminiscent of the original person.

"I don't want to go down that hallway, there's a doppelfail of a kid I really hate."

doppelfail by Matt Coon September 17, 2007

Doppelfaust

German for "double fist". Colloquially used to describe the act of insterting two fists into the same orifice such as the vagina or anus.
The term retains it's German origins as it implies a far more brutal treatment to the more conventional practices of fisting.

Similarly it is used within the Metal culture to indicate aviolent arousal to someone/thing or to express a distaste for someone/something, depending on context. (See example two).

1. Hrafvnir doppelfausted Mary whilst she was chained to the bathroom floor. The screams were amazing, i think she's starting to like it these days.

2. "I'd doppelfaust that girl over there!" or alternatively: "look at that hige brutess over yonder, she needs a good doppefausting in her mouth!"

Doppelfaust by Bojan December 2, 2007

döppelfagger 

A person, who formally being homosexual, converts back to heterosexuality, but then is lured back to the other side, once more becoming homosexual.

"It's such a damn shame... we got him back onto the straight and narrow, but he had to attend that swinger party the other night. Some fella applied some pressure, and once again, he's licking the other side of the stamp"

"Crikey... a real case of being a döppelfagger"

döppelfagger by SmokeyJoeLincs October 9, 2007

Doppelwalker 

Someone who shares the same walk as a specific other person

Did you see how he was walking? Just like Dave! He’s his doppelwalker!

Doppelwalker by Keyhole Tony June 1, 2018

doppelgainer 

Someone who looks similar to someone else, but if the original person weighed more.

Omg, I just saw my doppelgainer; I need to go on a diet right now because I can never look like that fat bitch.

doppelgainer by Hank Moody69 December 6, 2017