Karaikal Ammaiyar was born in a Vaisya family. Punithavathy (Punithavathiar) was her original name. Danadathan was his father and Paramadattan, a wealthy Vaisya, was her husband. Karaikal Ammaiyar was an ardent devotee of
Lord Shiva and his Bhaktas(devotees.)
One day Paramadattan send two mangoes to his house. To serve mangoes for her husband at meal time, Punithavathy kept them safely. After sometime a hungry Shiva Yogi came there. She worshipped him and offered one mango. Later, when Paramadattan came she served him with remaining one mango. He liked its taste and asked her for the other one. She became upset, and prayed the Lord. Mysteriously a mango fell on her palm. She served it to her husband. Tasting its exceptional sweet, he was sure that it was not one he had sent. Punithavathy told him about all incidents happened. To make understood him she again prayed, and another mango appeared. But the mango disappeared when she gave it to his hand. Paramadattan surprised with his wife's greatness and think that it was a great sin to live with her as husband. So he disappeared from there and married other women.
When he had a child, he put her name Punithavathy. Punithavathy and her family came to know about the whereabouts of Paramadattan, and they went to see him. On seeing her, Paramadattan and his new family fell at Punithavathy’s feet. His explanation was that he regarded Punithavathy not as wife, but as a Goddess. Punithavathy understood his condition and prayed the Lord to give her demoniacal form. The Lord accepted her prayer and then she entered the Lord’s abode.
[Source (7) 03-June-2005]
