Quote: "I'll hit you so hard I'll kill your whole family." Fenwick, a character in the 1982 movie "Diner"
Figure of Speech: perclusio (per CLOO see oh), the threat
The perclusio works especially well in concert with another figure of speech, the hyperbole. It also makes for great adolescent banter -- a violent version of the insult game of Snaps.
Competitive discourse of this kind has a name all its own: eristic (eh RIS tick). Plato said its purpose is "victory in argument," rather than a search for the truth. He was a real hoot as a teenager.
Snappy Answer: "I'll hit you so hard you’ll have to unzip your pants to see out.”