My Aussie friend told me a good one
"He's got a roo loose in the top paddock"
Interesting one on here earlier " between the devil and the deep blue sea", as when I was a child in South Africa, there was an identical Afrikaans expression that meant someone was drunk.
Amazing I remember that as don't speak Afrik any longer, although I do understand it.
When she gets a nice surprise, my 89 year old friend always says "oh my ears and whiskers"