Why a particular part of the human body is referred to by the name of an animal(as an ***)?

Just think it over mate. Just like the ***, it is the most kicked and abused part of the male anatomy. As a child, it gets kicked and caned by your school teachers, as an adolescent, it is your parents' turn to kick you on that portion, later, during courtship, it is your girlfriend who makes taller and taller demands on your time, money and energy, and, if you are in no position to meet, them, kicks you and deserts you for greener pastures. If employed, your superior/s inevitably take sadistic delight in kicking it to their heart's content. Need I go on and tell what happens to a married man having. say, two kids ?

I don't know why butt was changed to an ***. don't make sense to me.

s***.

other name for Donkey

a word that always used for poles. ***

I think that's only for abusing.

that is four legged animal, this is stupid person, that is why

*** is also called by a good name moony you know..

the correct name for that part is anus

I think it is a word for denoting unpleasant things. So it could be used for butt.