There are a number of stories about how The Jade Emperor chose the dozen animals that would eventually represent the zodiac. One story says he needed 12 palace guards. During the process, each animal developed unique relationships with each other, which may explain the qualities and relationships they possess in the zodiac. For example, it is said during the sign up to become a guard, the Cat asked his neighbor the Rat to help him, but the Rat forgot, and they became mortal enemies. And as you know there is no Cat in the Chinese Zodiac.
At the palace, the placement in line determined what would eventually become the placement in the zodiac. After becoming angered by the Rabbit’s race with the Dragon, the Dog bit him in, and was sent to the back of the line as punishment. The Pig turned up late, and was behind the Dog. And of course, we find them as number 11 and 12 in today’s Chinese Zodiac. But a different story exists about the Jade Emperor, too busy to visit Earth growing curious about what the creatures looked like. He asked them to travel to the Heavens to visit him. And again in this story, we see traits, relationships and positions being formed. It is said the handsome Cat asked his friend the Rat to wake him in time for the meeting. But the Rat who felt ugly in comparison, failed to do so, and the Cat missed the meeting. Thereafter, they became enemies. And because the Cat missed the meeting, he was replaced by the Pig.
It is then said, the Jade Emperor divided the years amongst them. A third story details the Emperor on his birthday, calling a race of all animals with a restriction on just 12 winners. The animals had to cross a rapid current. It is said the animosity between the Cat and the Rat started when the Rat pushed the Cat into the river, after the Ox gave them both a ride. Once arriving on shore, the Rat raced the Ox and won, and hence, we see them as position one, and two in the Zodiac. But this story is debated, with others saying it was the Buddha who called the race and not The Jade Emperor.
So how did the Emperor choose those 12 animals, and was it really him who did so?
We may never know, but without question, the mythologies surrounding the zodiac are all beautiful and mystical, not to mention relevant to the zodiac as we know it today.