"Damn...that's the jibberknacker, man!!"
When a guy always gets the girl, people say, "He's the jibberknacker, man!"
After a large explosion, "Damn what a jibbernacker!"
People shouting during a boxing match "Give him the Jibberknacker!!"
People use this to mean macho or wiseguy or weed or a-punch-in-the-face