To be 'quacked' is to see (or more likely shown) a video of a good beautiful girl but at the last second it turns out she has a penis. The reveal is usually accompanied with a cartoonish duck's quack, hence 'quacked'.
My bro showed me this video of this smoking hot chick and I was like "ooooweee!" But then she turned around and there was a big ol' cock n balls. Dude quacked me!
When something is absolutely bonkers in your mind to the point of it emitting a feeling of power in a good way, or when something is indescribably good and/or meaningful to someone.
Person 1: Bro why do you eat nesquik powder so much. There's no way that can't be healthy.
Person 2: Dog its just so good there is no words on god's green earth that can describe how fucking good this is.
Person 1: Ain't no way that shit is that good man.