(Lakota = "double woman") Wiya Numpa is a hermaphrodite spirit, that if appearing to either males or females, required them to adopt the dress and lifestyle of the opposite sex.
"When a woman dreams of the Double Woman, from that time on, in everything she makes, no one excels her. But then the woman is very much like a crazy woman. She laughs uncontrollably and so time and again she acts deceptively. She causes all men who stand near her to become possessed.
For that reason these women are called Double Women. They are very promiscuous, having many husbands. But then in the things they make no one excels them. They do much quillwork. From then on, they are very skillful. They also do work like a man... Even now, they believe these things are holy."
Source: received from: Thomas Tyon (Lakota American)