a can of whoopass - A can of whoopass is when you're about to get your face smas

A can of whoopass is when you're about to get your face smashed like a rotten tomato.

My friend opened a can of whoopass on me. I now have a black eye and a broken nose.

My dog opened a can of whoopass on my neighbor. The neighbor ran away screaming.

I opened a can of whoopass on my brother. He's now in the hospital.