"Karthikeya" or 'Muruga" as He is known to devout Tamilians, is mythologically the second son of Lord Shiva and Mother Parvathi. Interesting and inspiring are His birth and feats, which are elaborately described in the 'Skanda Purana', an epic that is as revered as the Ramayana or the Mahabharata by South Indians.
"Murugu" in chaste Tamil means "beauty". Extolled as the epitome of beauty, valour and "Jnana" [Supreme Knowledge], Muruga is worshipped in several ways, through various rituals. One of these is the bearing of "Kavadi" by the devotee.
But he was baffled as to how he could lift them. Divine help came in the form of Brahma's 'danda' [thick stick] poised over the two hillocks, while the celestial snakes fastened themselves to the rod like ropes. Idumban slung the hillocks over his shoulders and proceeded southward. Near Palani in South India [where a famous shrine of Muruga exists], Idumban kept his burden down to rest awhile. When he attempted to lift the hillocks again to continue with his journey, he found that the hillocks were rooted to the spot!
Idumban spotted a youth with a stick wearing only a loin cloth round his waist. On being approached for help for lifting the hillocks, the youth nonchalantly replied that the hillocks belonged to him! In the scuffle that ensued between the angry Idumban and the scantily clad youth, Idumban was defeated. Only then did Idumban realize that the youth was none other than Muruga or "Subrahmanya" Himself - the ruling deity of the region. Idumban craved the pardon of the divine youth and also sought the boon that anyone who comes to the hills to worship Muruga with an object similar to the two hillocks suspended by a rod, may be granted his heart's desire. Idumban's wish was granted.
"Kavadi" appears to be a word of Tamil origin - a combination of the words 'kavi' and 'adi'. 'Kavi' means 'saffron' implying asceticism and 'adi' means 'foot' signifying pilgrimage. Taken together the significance of the word is very clear. The devotee takes a vow to live the life of an ascetic for a particular period and then, as the culmination, travels to the temple of Muruga by foot, bearing that symbol of purity - the "Kavadi".
There are different kinds of "Kavadi" of which the most prevalent are " Annakkavadi", and "Palkavadi". "Annakkavadi" entails the devotee going barefoot from house to house, begging for food, not with the motive of satisfying his own hunger, but as offering to the Lord and his devotees. This custom helps in inculcating humility in the devotee who has to beg for food, whatever his social standing may be. In "Palkavadi" the devotee begs for milk, which is ultimately offered to the Lord and His devotees. There are several variations in the idea, but the basic objective is to destroy the devotees's ego, so that he comes nearer to Divinity.