The Chinese zodiac has 12 animals in its repeating cycle.
The standard order is Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, and Pig. Each animal governs one year before the next sign takes its place, and the sequence returns to the Rat after the Pig.
The 12-year pattern is related to the traditional Chinese method of tracking Jupiter's approximate 12-year orbit around the Sun. Historical calendrical systems also used repeating earthly branches, which became associated with the animal signs. The familiar zodiac has changed in details across regions and periods, but the 12-animal structure is the best-known form.
The 12 animals are only part of the traditional designation. Each year also carries one of five elements, and the pairing of animal and element creates a 60-year cycle. Consequently, calling someone simply a “Dragon” leaves out the element and does not identify the complete traditional year name.