be as cruel as a wolf
Wolf heart and dog lung, a Chinese idiom, Pinyin is l á NGX ī ng ǒ UF è I, which means to describe the heart as vicious as wolf and dog. It's from xingshihengyan.
The origin of Idioms
In Ming Dynasty, Feng Menglong's "awakening the world" volume 30: "I know this thief is so ungrateful and ungrateful."
Idiom usage
You rotten son of a bitch, you want to piss me off. You've lived a happy life. The 12th chapter of China now by Li Baojia in Qing Dynasty
be as cruel as a wolf
look for release through the pain - bù gǎi qí lè
Keep your lips close to your cheeks - chún bù lí sāi
take advantage of another 's perilous state - chèn rén zhī wēi