Why are there no pandas in the zodiac?

Due to historical and cultural reasons, there are no pandas in the zodiac.

Zodiac evolved from the twelve earthly branches and became popular in the Northern Zhou Dynasty during the Southern and Northern Dynasties in China. Pandas were regarded as rare animals in ancient times, and most people were not familiar with them. In addition, zodiac animals are mostly common in the daily life of the ancients, while pandas mainly live in deep mountains and forests, and people have less opportunities to contact them. So pandas are not among the zodiac animals.