You chicken.
你这个胆小鬼.
I heard a story about it, so i knew the sentence.
in china,we often use the mouse instead of it.and "chicken " isn't a good word in some way.
but in America,they use chicken to denote cowardice,
one day,an American said that you chicken to a girl who is a chinese,and the girl was very sad!
at that moment,he did'n't kown that's why!