Meaning of proverb 어물전 망신은 꼴뚜기가 시킨다

어물전 망신은 꼴뚜기가 시킨다

It's a proverb in Korea which means "One bad person brings disgrace to his/her colleague/family/group."

To know it's literal meaning, we can divide the proverb into 3 parts :

어물전 : (魚物廛) fish stores (fishmongers) that existed in Chosun era.

망신시킨다 : to disgrace, to embarrass

꼴뚜기 : pencil squid

So we can interpret the sentence as :

"The pencil squid brings disgrace to the fish shop."

In Korean proverbs, 꼴뚜기(pencil squid) is often portrayed as someone(something) who does something that damages one's reputation or does something that doesn't get any respect from others.

one example would be "망둥이가 뛰니 꼴뚜기도 뛴다 (Pencil squid jumps when mudskipper jumps)" which can be used when we see someone who doesn't have his/her own belief.

This is because 꼴뚜기 is considered to be one of ugly creatures in Korea. When customers saw 꼴뚜기 in 어물전, they wouldn't buy it, and some customers even left the store because they didn't want to look at that ugly creature.

Some usage example of "어물전 망신은 꼴뚜기가 시킨다" would be :

1. When a member of a band commits crime.
2. When traveler does something that would damage his/her country's reputation.
3. When a famous person's son/daughter posts a controversial post in SNS.

So we can see the nuance of this proverb is very negative towards the subject.