The vehicles carrying the pilgrims to Sabarimala from various parts of the country are pooled at Erumeli. An Ayyappa Temple is built here and its idol is in the form of an archer. An archer obviously is bent upon hitting a target. This implies that the devotee shall concentrate on his goal of reaching the presence of the Lord i.e., God-realization. The path of God-realization is not smooth and comfortable, but full of trials and tribulations. The route ahead of Erumeli, full of pains and perils, represents this.
The name of the place ‘Erumeli' owes it origin to the episode of killing 'Mahishi'. 'Mahishi' is Sanskrit word whose Malayalam equivalent is 'Eruma meaning she-buffalo. ‘Eruma ' was killed at this place by Manikanta. So the place came to be known as ‘Erumakkolli', which later on degenerated into 'Erumeli '.
Not far from the main Ayyappa temple at Erumeli, there are two other small shrines, one dedicated to Vavar and the other to Ayyappa himself. The inhabitants in the vicinity of Vavar temple are mostly Muslims who join hands with the pilgrims of Sabarimala to participate in the festivities. Vavar was a trusted Muslim associate of Ayyappa in all his ventures of suppressing the miscreants. These two tiny shrines are at Petta.
‘Petta thullal' at Erumeli is a spectacular event in the course of the pilgrimage. The pilgrims paint themselves in dots and stripes with ashes, saffron and carbon and appear odd-looking carrying arrows, clubs, bundles containing fruits and vegetables tied to the top. With the Kanni Ayyappas in the front rank, they begin to dance rhythmically to the accompaniments of drums and cymbals. Slogans of 'Ayyappan thinthaka thom, Swarni thinthaka thom ' bursting out of the throats of excited devotees rend the sky. As the hectic dance gains momentum the slogans grow louder and louder. The slogan is an invocation for filling the aspirant's heart with the thoughts of the Lord.
Petta thullal starts from the small shrine and proceeds to the main temple. As the dancers reach the main temple the branches of trees are thrown on its roof and they circumambulate the temple. After the burning of camphor before the deity the dance is concluded. It is obligatory on the part of Kanni Ayyappans to participate in Petta thullal.
Petta thullal of pilgrims from Ambalappuzha and Alangad are of special mention. Ambalapuzha Petta thullal starts first. It begins at about 12 Noon on 27th of the month of Dhanu. The Petta thullal starts only when a kite is found hovering over the small shrine. The deity of Ambalapuzha temple Sri Krishna, is supposed to have arrived on his carrier Garuda, to witness the scene. It is rather miraculous that the kite appears there every year at the appropriate time. The Petta thullal takes about three hours to reach the main temple. By that time it is about 4 p.m. and a silver star is found rising up above the eastern horizon. On seeing the star, Alangad party begins their turn for Petta thullal. They are usually accompanied by two caparisoned elephants bearing the idols of Ayyappa and Maheswara. Unlike the pilgrims from Ambalapuzha who are dressed like forestdwellers, the members of Alangad group are dressed like bodyguards. They smear their bodies with Kalabha.
As the legend goes Pettathullal is a commemoration of the rejoicings of the people after Mahishi was killed by Manikanta.