The first animal in the Chinese zodiac cycle is the Rat.
The Rat begins the repeating twelve-animal cycle used in the Chinese calendar. It is followed by the Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, and Pig. The zodiac sign is connected with the Earthly Branch zi, the first branch in the traditional sequence.
The Rat also has calendar associations beyond the yearly cycle. In the traditional system, the Rat corresponds to a two-hour period around midnight, from 11 p.m. to 1 a.m., as well as a month and a daily branch. Each Rat year is paired with one of the Five Phases—Wood, Fire, Earth, Metal, or Water—creating a sixty-year cycle when combined with the Heavenly Stems.
A popular legend says the zodiac order was settled through a race, in which the Rat used cleverness to finish first. That story explains the sequence culturally, but the zodiac itself is a calendrical tradition rather than a scientific system of personality types. The Dragon is famous and auspicious, but it is fifth, not first.