We use donkey (خر) to exaggerate things in the Persian language!!!!!
I'm going to tell you an interesting fact about Persian language.
In Persian language, if you want to say that something is very big or too much, you will add خر (khar - donkey) to that word. for example:
خرگوش = khargoosh - rabbit : this word means that this animal, has "very big ears".
خرمگس = kharmagas - wasp (an insect) : this word means that this bee-like insect, is very big.
خرخون = kharkhoon - nerd (a student who studies a lot!) : "khoon" means reading and studying and this whole word means someone who studies a lot.
خرشانس = kharshans - very lucky : this expression is used for a person who is very lucky.
خرپول = kharpool - very rich : "pool - پول" means money and this whole word is used for a person with a lot of money.
Tell me your ideas about this fact in the comments.