Naropa taught different things to each of his students, and Niguma received the teachings that became known as the Nigu Chos-drug.
Once Niguma herself had reached enlightenment, she began to pass her knowledge on to others. Her most famous disciple was the Tibetan yogi and Bönpo Khyungpo Naljor, the only one to whom she imparted her most secret teachings. Therefore, the Shangpa school, although officially founded by Khyungpo Naljor, is in fact based on this transmission from Niguma.
When Khyungpo Naljor arrived at Niguma's dwelling place, the charnel ground of
Sosaling, she appeared to him as a dark brown dakini
dancing above him in the sky
adorned with ornaments of human bones. (Mullin, p.96).