Why is mustard called a one-eyed cat?

This name is because it has always appeared as a one-eyed cat in the comic book "Curse Back to War".

Mr. Jie Jianxia, male, born in Iwate Prefecture, Japan, is a famous Japanese cartoonist. He made his debut in 214, and his masterpiece "Curse Back to War", from which the word one-eyed cat comes.