The Chinese Zodiac is made up of 12 animals, rat, tiger, rabbit, dragon, snake, horse, ram, monkey, rooster, dog and boar. According to legend the Jade Emperor instructed the rat to find the animals and bring them to the bank of the river. In addition to the 12 animals mentioned a cat was also involved. The animals were to cross the river to the other side, the order in which they crossed would also determine the order they would be placed in on the zodiac. The rat and cat decided to be clever and ride across on the back of the ox. When they approached the far bank the rat pushed the cat into the water and jumped of the back of the ox to be placed first. The cat never made it out of the river and the boar was the last to cross. From that moment on the cat has been the sworn enemy of the rat.
In addition to the 12 signs of the zodiac the 5 elements of the earth (Feng Shui). The 5 elements are wood, fire earth metal (gold) and water. It is the combination of these two components which make up our zodiacal sign. Once a full cycle of zodiac animals has been made the elements will change. For example you could be a wood rooster or a gold dragon. This creates a 60 year cycle that starts with a wooden rat and ends with a water boar.
According to feng Shui each element has a cycle of creation and destruction. For example fire is created from wood but is destroyed by fire. Combining fire with any other elements created an unharmonious relationship. According to tradition marriages were arranged based on both components of the zodiac. Two people born under the sign of the rat were never married. However a person born as water rat would be supportive of a wood boar.