"Sure as there's shit in a cat".... indicating a sure thing
"The shit is out of the horse".... Indicating that it's too late to change, similar to "The toothpaste is out of the tube"
"Happy as a pig in shit"..... indicating that the person is in their element
It only just occurred to me how many of my idioms involve shit...
"So cheap he'd squeeze a nickel 'til the beaver farts"... This is a Canadianism, since our nickels have beavers on 'em. I suppose any of the commonwealth countries could say "squeeze a penny 'til the queen farts" or something to that effect
I've got lots of NSFW ones, too...
