There are 12 animals representing years as the mouse, the ox, the tiger, the rabbit, the dragon, the snake, the horse, the goat, the monkey, the rooster, the dog and the pig.

How come 12 animals designate years? There are different explanations about their origin. A popular legend says, long long ago, all the animals were ordered to pay a visit to the God of Heaven on New Year's Day, that is, the first day of the first lunar month. He said he would give the first 12 animals to come the title "King of the Animal World" and let each hold the title for one year. The 12 winners happened to be those mentioned above.

And how the unpleasant Mouse managed to be the first of the 12? As the story goes, when the Ox heard of the God's decree, he set out on the eve of the Lunar New Year. The Mouse jumped onto his back without being noticed. When the Ox arrived, the Mouse jumped down over the Ox's head and became the first to kowtow to the God. So he was appointed the first King of the Animals.

The Mouse also had played a trick on the Cat by telling him a wrong date, which makes the Cat a day late getting to the God's place, thus failed to be chosen. This is the reason why the Cat hates the Mouse ever since.