英语中把代人受罪、替人“背锅”的人称为“scapegoat”，意思就是替罪羊，把家族中有辱门第的成员称为“black sheep”，相当于中文里的败家子、害群之马。可你知道为什么替罪的、败家的偏偏是羊，而不是猫、狗、猪、牛或者其他动物吗？

Scapegoat

例句：

I don't think I deserve to be made the scapegoat for a couple of bad results.
我认为我不该为出现的一些不良后果充当替罪羊。

The word scapegoat was first coined by English Protestant scholar William Tyndale in his 1530 English translation of the Bible, according to a book written by David Dawson. Tyndale, who was deciphering Hebrew descriptions of Yom Kippur rituals from the Book of Leviticus, recounted a ceremony in which one of two goats was selected by lot. A high priest would place his hands on the goat’s head and confess his people's sins— thus transferring them to the animal—before casting it out into the wilderness to rid Israel of its transgressions. As for the other goat, it would be sacrificed to the Lord.
根据大卫•达沃森的著作，scapegoat（替罪羊）一词是英国新教学者威廉•廷代尔最先发明的，他在1530年的英译版《圣经》中创造了这个词。廷代尔将《利未记》中关于犹太人赎罪日仪式的希伯来文描述翻译成英文，在这个仪式上，两只山羊中有一只被命运选中。大祭司要把手放在被选中的那只山羊头顶，以宽恕上帝的子民犯下的罪行（这个动作表示把罪恶转移到山羊身上），然后将山羊放生，从而帮以色列人赎罪。至于另外一只羊，则将作为牺牲献给上帝。

Tyndale coined the word scapegoat to describe the sin-bearing creature, interpreting the Hebrew word azazel or Azazel as ez ozel, or "the goat that departs or escapes." That said, some scholars have disagreed with his interpretation, claiming that Azazel actually stands for the name of a goat-like wilderness demon, whom the offering was meant for, or a specific location in the desert to where sins were banished, often thought to be a mountainous cliff from which the scapegoat was cast off and killed.
为了诠释希伯来语单词Azazel（逃跑的山羊）的意思，廷代尔创造了scapegoat一词，用来指代承担罪行的生物。据说，有些学者并不赞同廷代尔的解释，认为Azazel实际上是指一个存在于荒野间的酷似山羊的恶魔，而祭祀的山羊就是为它准备的。又或者Azazel指的是沙漠中某处可以洗刷罪恶的地点，人们一般认为是一处将替罪羊抛下来杀死的高耸峭壁。

Over the centuries, the word scapegoat became disassociated with its Biblical meaning, and it eventually became used as a metaphor to describe a person who shoulders the blame of any wrongdoing.
几个世纪以来，scapegoat这个单词已经和圣经里的意思无关了，它最终用来指代承担所有罪责的人。

至于black sheep，如果你以为是“黑色的绵羊”，那可就大错特错了。

Black sheep

例句：

As the owner of the factory I'm like the head of a family, and as such I can't allow any black sheep among my employees.
我在厂里好比是一家之主，我不能容忍那种害群之马。

In the English language, black sheep is an idiom used to describe an odd or disreputable member of a group, especially within a family. The term stems from the genetic effect in sheep whereby a recessive gene occasionally manifests in the birth of a sheep with black rather than white coloring; these sheep stand out in the flock and their wool was traditionally considered less valuable.
在英语中，black sheep这个习语用于形容群体中格格不入或者声名狼藉的成员，尤其是家族中。这种说法来自于绵羊的一种遗传效应，有些新生绵羊因发生隐性遗传长成了黑色，而不是白色，这些羊在羊群中格外扎眼，而它们的羊毛通常没有什么价值。

Black wool was considered commercially undesirable because it could not be dyed. In 18th and 19th century England, the black color of the sheep was seen as the mark of the devil.
由于黑色的羊毛无法染色，因此没有什么商业价值。在18世纪至19世纪的英格兰，黑色的绵羊被视为魔鬼的象征。

In modern usage, the expression has lost some of its negative connotations, though the term is usually given to the member of a group who has certain characteristics or lack thereof deemed undesirable by that group.

在现代用语中，关于black sheep的一些负面含义已经消失，不过，这个习语还是经常被用来形容群体中因具有某种特殊特征或缺陷，而不受该群体欢迎的成员。

（来源：英语点津）