I know that a translation of the word “puppy” can be an insult/cuss word, but does anyone know why exactly?
Why is “puppy” a cuss word in korean?
The most common translation of 'puppy', 강아지 , isn't commonly used as an insult.
a translation of the word “puppy” can be an insult/cuss word.
I guess the particular translation you mean is 개새끼 - more literally "offspring of a dog" - offensive for much the same reasons as "son of a bitch" in English, as per jick's comment.