What is your favorite insult in your native language that doesn't exist or cant be directly translated in English?

Oh, I've several. Irish people love a good curse.

Go mbrise an diabhal do dhá chois May the devil break your legs

Go ndéana an diabhal dréimire do chnámh do dhroma May the devil make a ladder out of your spine

Go n-imí an droch aimsir leat That the bad weather leaves with you

Go n-ithe an cat thú is go n-ithe an diabhal an cat May the cat eat you and may the devil eat the cat

And my personal favourite: Lá breá ag do chairde, dod adhlacadh May your friends have a fine day, burying you