"I'm gonna open up a can of whoop-ass on ya", a common threat used in the late 1990's to imply that if an individual did something, or did not stop doing something you were going to beat them severly. The severity of the beating could be altered by changing the "container" which was to be full of "whoop-ass"

"I'm gonna tap a keg of whoop-ass"

I'm gonna open up a 55 gallon drum of whoop-ass"

I'm gonna pop the top on this 8 oz. can of whoop-ass"