Dutch has a lot of funny idioms! I will name a few:

Literally translated: As crazy as a door.

We use this to say that someone is really crazy (he is as crazy as a door). I don't know the origin of this idiom however (maybe according to the Dutch, doors are really weird...?)

Literally translated: Now the monkey comes out of your sleeve.

We say this when we figure out the truth about something.

Literally translated: Laughing like a farmer with a toothache.

This is the case when someone makes a joke and you don't get it, or you don't find it funny, but still you try to laugh along. Then you would be laughing like a farmer with a toothache :)

Literally translated: Getting out of the west.

This is when for some reason you went knock out, you lost consciousness. Then we say that you were getting out of the west XD

Literally translated: Being as fed up as a plug.

When something happens and you're really disappointed about it, then you're being as fed up as a plug :)

Literally translated: That's a different cookie.

We say this to indicate that something is totally different. For instance when you're having a conversation about languages and all out of the sudden one starts talking about mathematics, then the Dutch would say: "That's a different cookie."

Literally translated: As if an angel is peeing over your tongue.

This means that something is actually really delicious!

Literally translated: To bump into the lampshade.

This is when someone is being caught in the act when committing a crime or some other kind of misdeed.

There are many more but I could spend a lifetime writing them all down :)

يا ماخذ القرد على ماله بروح المال وبظل القرد على حاله

It talks about gold diggers who marry men only for their money.

اقلب الجرّة على فمها، بتطلع البنت لأمها

This one indicates that girls will turn to be exactly like their mothers.

لما ينوّر الملح

This indicates that something isn't going to happen because it's impossible.

ذنب الكلب أعوج

This one indicates that some people would never change!

Freci menta – You are rubbing the mint: you are wasting time. We also use another expression for this: Tai frunză la caini – You are cutting leaves for the dogs. Both of them basically mean 'doing nothing'.

Umbli cu cioara vopsită – You are walking around with the painted crow: you are trying to fool somebody, or you are telling a lie.

A fi prins cu mâța-n sac – To be caught with the cat in the bag: used when trying to say that somebody was caught lying or cheating; similar to the expression 'to be caught red handed'.

Am eu ac de cojocul tau – I have the needle for your coat: we know exactly what to do to get back at somebody, to take revenge.

Te duce cu preșul – He carries you with the rug: somebody is not being honest with you, they are trying to fool you.

A bagă mâna-n foc pentru cineva – To put your hand in the fire for somebody: you vouch for somebody.

Mi-a picat fisa – My coin dropped: I finally got it, I finally understood something.

La Pastele cailor – At the horses’ Easter: used when you want to say that something will happen very far in the future, or most likely never.

Ma scoți din pepeni – You take me out of the watermelons: we are getting really angry.

A vinde gogosi – Selling donuts: I believe you are lying.

Esti dus cu pluta – You’re gone on a raft: I believe you are crazy, that you’ve lost your mind.

Vinzi castraveti gradinarului – You’re selling cucumbers to the gardener: you are trying to lie to somebody who knows the truth, or to explain something to somebody who already knows more about the issue.

Mi-a ajuns cutitul la os – The knife has reached my bone: I can’t take it any more.

(source: Romania-insider)

Some funny Australian idioms:

A dog's breakfast - something messy or disorganised

A face like a smashed crab - to describe someone who is ugly

To have a few kangaroos loose in the top paddock - to be crazy

I'm not here to f*** spiders - a response when somebody asks you something where the answer is already obvious. For example if you were at a football stadium and somebody asked you "Are you here to watch the football?" you could reply "Well I'm not here to f*** spiders."

Going off like a frog in a sock - when something (eg a party) is very exciting or crazy but in a good way

Budgie smugglers - a term for men's swimming briefs

Better than a poke in the eye with a burnt stick - the situation could be worse

When you think about it, "wrap your head around it" is a funny idiom. It's usually used in the negative..."I can't wrap my head around it" means "I can't understand it, it's too complicated". Some problems are so complicated that you just have to guess at the solution, but then you're usually "barking up the wrong tree". What a funny expression. How insulting! :) To be compared to a dog who doesn't know which tree the squirrel climbed up! All this dog can hope for is a kind owner who is willing to "spill the beans" and point him to the correct tree. "Spill the beans" means to let someone know a secret. How did this come about? Did people hid their secrets in sacks of beans in the good ol' days? I think I read that somewhere, but they could have been "pulling my leg". When you think about it, it would be much easier to tell when people were just kidding if they actually DID pull your leg when they were doing it. Don't you think? Perhaps that's a "bridge too far".