In China, everyone has their own Chinese zodiac that is represented by twelve kinds of animals. Unlike the twelve constellations, the Chinese zodiac depends on which lunar year you are born. The Chinese zodiac includes animals such as pigs and dogs, but some people wonder why a common animal such as the cat isn't included in it. This is due to the fact that the Chinese zodiac was invented in the Han dynasty, around 200 years BC, and in those years the cat hadn't been introduced in China.