According to one legend, the Jade Emperor invited all the animals in creation to a race, only twelve showed up: the Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, and Pig, and according to their places in the race, the Jade Emperor had given them each a number starting with the Rat who was the winner of the race.
Many legends arose from the Race of the Chinese Zodiacs. One told of the reason why cats and rats shall always be enemies: He and the cat (at the time good friends) were poor swimmers, so they asked the ox if they could stay on top of his head to cross the river. Along the way he pushed the cat off the ox's back. And the cat, incapable of swimming, lagged behind. The rat stayed on top of the ox's head until the ox was almost at the finish line. And as the ox was about to cross it, the rat jumped from the ox's head and became first place. And the cat and rat have been enemies ever since.
Another legend tells that the cat had asked the rat to wake him up the day of the Race. The rat agreed, but on the said day, he did not wake the cat in his greed to win. When the cat finally woke up and got to the racing ground, he found the race to be over. The cat then swore revenge upon the rat. (Source: Wikipedia)
Dragon - a favourite with many chinese and that is why there is always a baby boom during the year of the dragon. This is not good cause getting a place in the school can be a problem when the baby grows up as there are too many vying for a place in a popular school.