人面兽心的英文：
[Literal Meaning]
human/face/beast/heart
to have the face of a man but the heart of a beast

[解释]
虽然长着人的脸，但是心却像野兽。形容为人凶残、卑鄙。

[Explanation]
very evil

[例子]
我们千万不能放过那个人面兽心的家伙，他干的坏事太多了。

[Example]
We must not let that evil guy off. He did so many evil things!

[英文等价词]
a fiend in human shape
a beast in human face

Human vultures who ran sweatshop factories in firetrap tenements were all too willing to take crippled workers
在设有避火设备的廉价公寓中开设“血汗工场”的人面兽心的贪心汉，他们都非常愿意雇用残废的工人。

The scoundrel had the face of a human being , but the heart of a beast.
那个歹徒人面兽心。

His cruelty marks him as a brute.
他的残忍表明他是个人面兽心的家伙。