Bronze Charm with Chinese Zodiac, 1000-1400 AD.
This is not a coin but a bronze charm. The reverse is Chinese Zodiac. The outer circle are the twelve figures, and the inner circle are the corresponding Chinese characters. The obverse are two immortals with a turtle at foot, meaning long life I guess. From the style and the patina, I guess it's casted between Song and Yuan dynasty, about 1000-1400 AD.