Shut your piehole! means “Shut your mouth!” Need more slang terms for the mouth? For starters, there’s potato trap, tater trap, tatty trap, bun trap, gingerbread trap, kissing trap, fly trap, rattle trap, baconhole, and cakehole...
If you’re in New Zealand and are told to “rattle your dags,” you’d better get a move on. Literally, though, the expression has to do with sheep butts. This is part of a complete episode.