There is a misconception among many people that Vettakkorumakan is Lord Ayyappa. Actually, Lord Ayyappa was born to Mohini and Lord Siva.
Arjuna was doing a penance to please Lord Siva to get boon which would help him during the war of Kurukshetra. Arjuna had in fact become too proud of his archery abilities and Lord Siva and Goddess Parvathi wanted to teach him a lesson. Vettakkorumakan was born from the union of Lord Siva and Goddess Parvathi when they took the form of hunters to test Arjuna.
This boy born to Siva and Parvathi becomes extremely naughty and was a menace to the people including saints. Based on their request, Maha Vishnu disguises as a hunter and invites him for a duel. During the duel Vettakkorumakan sensing a divinity in his opponent, asked, "Daivathil aar?" To which he received the reply "Daivathar". Vettakkorumakan soon became interested in a novel weapon which he observed in the waist band of his opponent. Sensing his desire to possess the weapon, Daivathar put forth a condition. Vettakkorumakan can have the churika on his right hand provided he will never put it down on the earth. Vettakkorumakan soon realized that the churika is increasingly becoming heavier. His pride soon vanished and entered a truce with Daivathar.
This is a legend associated with Sree Oorpazhachi Kavu. It is a temple in the Edakkad grama panchayat in Kannur District of Kerala, India. Vettakkorumakan has a fierce form carrying bow, arrows, swords etc. This war Lord is easily pleased with offerings of coconut.