* you're as behind as a pig's tail!
It's used to address someone who isn't very bright or who just acted stupid or made a stupid mistake.
"G'ho coresto drio a l'orso per farghe na foto ma el s'ha girá e 'l m'ha dato na zatada!" "Alora te si ndrio come la coa del porco!"
"I was chasing a bear to take a picture of it, but he turned around and attacked me!" "Then you're as behind as a pig's tail!"