Most difficult openings to play against

What are some of the most difficult openings by white to play against? They are not necessarily good openings, but are very complex/risky/weird making them difficult to counter as black. Share your top picks! 

Elephant Gambit and Rosseau Gambit.

alíen gambit

ORUGUTAN

so hard, so hard

QGD

Yugoslav attack of dragon sicilian

Alien Gambit is easy enough to counter

London

Bong cloud

Italian, Open Catalan, Caro-Kann, Pirc...

Ah I mentioned the openings that are hard to play as black...with White everything is kinda okay...

Maybe Nimzo-Larsen...

I learned a trap in the pirc that makes it easier to counter.