Chang-O (also Chang-Er, Chang-e, Hang-O) is the Chinese Goddess of the Moon and sister to the river god He-bo (He-po, Ho-po, Bing-yi, Ping-i) and wife to Yi (Hau-yi, Hou-yi, Shen-yi), the Celestial Archer.
She is perhaps best known for stealing a potion of immortality from Her husband. (He had received the potion as a gift for destroying all by one of the suns that circled the Earth.) However, He stopped Her before She could drink all of it. She had drunk enough to ascend toward heaven, but was only able to get as far as the moon. There She sits, with Her beautiful robes draped over the lunar crescent. Some versions of this myth, however, say that when She got to the moon, She was transformed into a toad. She is also sometimes shown sitting with the Jade Rabbit, also said to be an inhabitant of the moon. (If you look closely on a night when the moon is nearly full, you can sometimes see a dark area that looks very much like a rabbit.)
Chang-O is known to give good fortune to those who remember to honour Her. She is also kind to romantic couples, as She was separated from Her husband. Her festival, the Moon Festival, is celebrated on the fifteenth day of the eight lunar month. She also represents the Yin principle.