I've seen more meat on a butchers pencil
It's a well known fact that butchers write notes to their loved ones with the shank of a pheasant.
Some other idioms that might stump people:
The last straw: this originated in the McDonalds franchise on Aigburth Road, when a 'drive-thru' customer asked for a second straw for his McChicken McFlushy. Mary-Ann, at window one at the time, informed the gentleman that 'that was the last straw' when, by chance, a camel dropped from the sky and crushed him and the 97 off-white Fiat Panda in which he lived. Commonly used when something bad is about to happen.
In the land of Nod: A Swiftian pun on Cain's exile in Genesis, now exclusively used for people working on the estate of Noddy Holder.
Kettle of Fish: a Scottish borders term for when you wake up and find lots of fish inside your kettle, which normally happens at least twice a week in that part of the world. Most often used today as 'a different kettle of fish,' which is when you wake up to a lot of fish inside a kettle that you have no recollection of purchasing.
Greasing the palm: bribing a fat politician with a handful of delicious Lurpack Spreadable, circa 2014
To curry flavour: this, quite simply, means to pour curry on your school-packed-lunch processed turkey sandwiches in order to feel alive. Commonly used today for literally blowing madras powder into the eyes of uninteresting people in order to watch them flail amusingly. Commonly mistaken for
curry favour, which means to buy your mate a vindaloo on your way home from the Raz.
The Pope is inflammable: the Catholic belief that, no matter how hard they may try, the Pope has no sustainable ignition points. Commonly used to suggest that, because all liars burst into flames, he must be right about most things.