A lesser known story from the Brahma Vaivarta Purana narrates a different version of Ganesha’s birth. On the insistence of Shiva, Parvati fasted for a year (punyaka vrata) to propitiate Vishnu so that he would grant her a son. Lord Vishnu, after the completion of the sacrifice, announced that he would incarnate himself as her son in every kalpa (eon).
Accordingly, Krishna was born to Parvati as a charming infant. This event was celebrated with great enthusiasm and all the gods were invited to take a look at the baby. However Shani (Saturn), the son of Surya, hesitated to look at the baby since Shani was cursed with the gaze of destruction.
However Parvati insisted that he look at the baby, which Shani did, and immediately the infant’s head fell off and flew to Goloka. Seeing Shiva and Parvati grief-stricken, Vishnu mounted on Garuda, his divine eagle, and rushed to the banks of the Pushpa-Bhadra river, from where he brought back the head of a young elephant. The head of the elephant was joined with the headless body of Parvati’s son, thus reviving him. The infant was named Ganesha and all the Gods blessed Ganesha and wished Him power and prosperity.