At olden times in Kerala, India, the people were divided into different castes (according to the work they did). A Pulluvan is a male member (female Pulluvatti ) of low caste group called Pulluvar. The term pullu means a bird of omen. The term pulluvan must have meant ‘a person who predicts from the sound of birds’. There are many sub-divisions within the Pulluva community. The majority among them are called Nagampatikal (People who sing snake-songs). There are pulluvars who are not Naagampatikal, as well. They are known as Pretampatikal (People who sing ghost songs).
Art forms

Most of the art forms of the Pulluvar are ritualistic. Most of their songs are related to worship, ritual, custom and exorcism. The pulluva art is expressed in the background of snake-worship, ghost worship and magic.

The pulluvar of Kerala are closely connected to the serpent worship. One group among these people consider the snake gods as their presiding deity and perform certain rituals such as sacrifices and song singing. This is called ’Pulluvan Pattu’. This is performed in the houses of the lower castes as well as those of the higher castes, as well as in serpent temples.

The song conducted by the pulluvar in serpent temples and snake groves is called Sarppapaattu, Naagam Paattu, Sarpam Thullal, Sarppolsavam, Paambum Thullal or Paambum Kalam. The main aspects of this are Kalamezhuthu (Drawing of Kalam, a ritual art by itself), singing and dancing.
Ritual

The women of the house where the ritual takes place performs the serpent dance (Sarpam Thullal). Austerities start seven days or nine days prior to the day of the dance. They avoid eating certain food items that are considered to be impure. The canopy (pandal) where the serpent dance takes place is adorned with palm leaves, granium flowers, jasmine flowers, chrysanthemum indicum, champaka, lotus, banyan leaf, betel leaf, ripe arecanut and branches of coconut flowers. The form of the serpent is drawn with rice powder (white) and colour powder (black, red, green, yellow). The Pulluvar conduct the ritual around the decorated kalam (the field where the form of the serpent is drawn) in a specific order. The deities Nagas have different names as Naagaraajaavu, Naagayakshi, Sarppayakshi, Maninaagam, Erinaagam, Karinaagam, Kuzhinaagam, Paranaagam and Kanyaavu. The two women who represent the nagas in a possession trance come to the kalam and sit on the floor with an areca flower in hands. They circumambulate the Kalam three times before sitting.

The serpents are worshipped in front of the Kalam and are offered Noorum Paalum (Lime and Milk). After the pooja, the head of the family which conducts the Sarppam thullal gives bunches of areca flowers to the performers who start dancing rhythmically. They are supposed to represent the serpent gods, who accept offerings and grant boons to the devotees. The intensity of the dance heightens gradually. It is believed that prophesies which the dancer gives at the point of heightened intensity of the dance usually comes true. They fall on the floor in a trance and rub off the Kalam at the end.

Pulluvar songs are also sung on Aayilyam Pooja, day which is considered to be very auspicious. The presiding deity of the Aayilyam is the serpent.
Musical Instruments

The musical instruments used by the Pulluvar are pulluvan veena (a one stringed violin), pulluvan kutam (earthernware pot with on string attached to it) and thaalam (bell-metal cymbals). These instruments are made by the Pulluvar themselves.
The Veena

The Veena is made out of a hollow bamboo stick, wood shell and vegetal or brass wire. The Veena is played with a small arrow made out of a piece of bamboo.
The Kutam

The kutam is made of a pot on whose bottom a hole bored with calf skin is attached to the hole. Two small holes are made on the side where the skin is attached, and a string is tied to it. The other end of the string is tied to the end of a long stick. On the side where the string is attached to the stick is placed a small splint to elevate the stick. In order to restrict the movement of the stick, the other end is stamped down by the foot of the player. The string is called theru.
Main Temples

The main temples of Kerala where serpent is worshipped are Mannarassaala (Alappuzha District), Vetticode (Alappuzha District ), Kannannoor Devi Temple (Chennithala,Mavelikara,Alappuzha Dist),Paambu Mekkaat (Trichur District), Trippara Temple (Kollam district) and Ametamangalam (Ernakulam District). A very ancient temple where serpent worship is performed is Perasseri temple (Kannur District). The ritual is widely performed throughout Valluvanad.

For more information: https://en.wikipedia.org/wiki/Pulluvan_Paattu