Most of us know that Lord Shiva swallowed the Halahala. But, I have recently heard that a being called Bhuthathan was born from that poison. (You can learn about him from here)
AFAIK, the Maha Puranas mentiones that it was 100% swallowed by Lord Shiva.
So, my question is, Did Upa Puranas or any other scriptures mentiones about Bhuthathan's birth from Halahala (possibly they can mention Bhutathan in another name) or it is just a folklore?