狼心狗肺
Meaning
Cruel and ungrateful — someone who repays kindness with betrayal.
In a sentence
After all she did for him, calling him 狼心狗肺 felt fair.
Usage note
A strong insult. Use only in anger or in reported speech.
Where you see it in Brain Challenge
This idiom appears in the picture-idiom levels as a picture or number clue. When the clue shows numbers, the digits usually become the first characters of each half of the idiom — that is why so many chengyu start with 一, 三, 五, 七, 九 or 十.