This day entire snake family got a new lease of life . It’s considered a sacred day by Hindus. The festival Nag Panchami is celebrated on this day. The five Nagas worshipped Nag Panchami are Ananta, Vasuki,
Ta ak, Karkotaka and Pingala.

It is also called Shraavan Shuddh Panchami (The fifth day of the Bright half of the Hindu month Shravan-July-August).
According to Varaha Purana, Lord Brahma’s son Kashyapa had four wives. Kashyapa’s first wife gave birth to Devas, second to Garudas, third to Nagas (snakes).

Fourth to Daityas (demons).
The third wife was called Kadroo, so Nagas are also known as Kadrooja.
She was mother of one thousand Nagas. Some prominent names being Sesha,Vasuki, Takshaka, Anant, Kanwal, Karkotak, Kalia, Aswatar, Padma, Mahapadma, Shankh, Kulik, Pingal etc.

When all these snakes started tormenting human-beings, lord Brahma cursed them that they would be annihilated due to the curse of their own mother.
The snakes got terrified and promised to mend their ways.

Requested lord Brahma to give them a place to live in. Lord Brahma instructed them to go to three different netherworlds-Sutal, Vital and Patal. He also warned them that during Vaivaswat manvantar Janmejay would perform a grand yagya.

The objective of destroying the wicked snakes but the virtuous among them would manage to survive.
 
ASIDE:- Their are several other legends n stories associated with
NAG PANCHAMI.
So please refrain from being too “GYANI”.

Yeh snakes nahi mutant snakes hai