Nagpanchami, the festival of snakes, falls on the fifth day of moonlit-fortnight in the month of Shravan (July/August) and is celebrated with much fanfare by Hindus.

During the festival, Hindu people paste pictures of Nagas (Snakes) containing mantras on the entrance to ward off natural calamities and evil spirits. The mantras mention eight principal nags, namely Ananta, Vashuki, Padhmanavha, Kambala, Shankhapala, Dhartarashtra, Takshyaka, and Kaliya. People also offer food items such as milk and honey in order to make Nag deity happy and ensure good health and prosperity. When happy, snakes are believed to bestow plenty of rain, which is good for crops but if the serpents become angry, people fall ill and no amount of medication can restore their health so people worship and try to make the deity happy by offering cow’s milk, lava, barley, sesame, nuts and other religious items.

Many legends are associated with the pious festival. According to Mahabharata, on the day of Shravan Panchami, Lord Krishna defeated Nag Kalia, a wicked serpent and put an end to his evil deeds. Another legend says that Kathmandu Valley was a big lake once. When human beings drained the lake to make space for settlements, Nagas became enraged. To protect themselves against the wraths of nagas, people offered to worship the serpents on a certain date in their habitats.

According to other scriptures, while ploughing the field, a farmer happened to kill some serpents. The mother of serpents took her revenge by stinging and killing all family members of the farmer except for one daughter, who was offering prayers to the nags. This act of devotion is said to have revived the dead family members and the Nag Panchami is observed to mark this occasion.

Similarly, the popular belief goes that monsoon is the period when snakes come out of the holes due to rain to seek shelter in gardens and nearby houses. Hence, Naag deity is invoked with prayers and ritual worships are worshipped with a belief in reward for this worship, snakes will never bite any member of the family. On this day, cultivation is prohibited because the serpents live under the earth and digging may hurt or annoy them. Some people also observe fast and offer prayers to Naag deity while some other people wearing demon masks dance in the streets as a part of a Nag Panchami ritual.

There are different myths and legends surrounding Nagpanchami and the tradition of snake worship is in vogue before the Vedic times till today