INTRODUCTION
Subramanya/Skanda/Kartikeya/Murugan is the son of Umadevi and Lord Shiva. He is the sena nayaka of the devata army and has the special presence of Bhagavan Vishnu, as Krishna says in the Bhagavad Gita:
पुरोधसां च मुख्यं मां विद्धि पार्थ बृहस्पतिम् ।
सेनानीनामहं स्कन्दः: सरसामस्मि सागर: ॥ 24॥
O Arjun, amongst priests, I am Brihaspati; amongst warrior chiefs I am Kartikeya; and amongst reservoirs of water, know Me to be the ocean.
[BhagavadGita 10.24]
Here, ‘Amongst warrior chiefs I am Kartikeya’ doesn’t literally mean that Krishna is Kartikeya, but it means that Kartikeya has the special presence of Bhagavan in him.
WHY IS SKANDA ASSOCIATED WITH A SERPENT?
This story comes in the Skanda Purana. Garuda and the serpents have a very great animosity, because earlier these serpents and their mother Kadru had tortured Garuda and his mother Vinata badly. So, Garuda kept attacking the snakes. That’s why, due to fear of Garuda, Vaasuki, the king of serpents, along with the other serpents, went to the dense forests of the Kukke Kshetra in the Biladvaara cave and was doing an intense penance with devotion.
Pleased by the intense devotion of Vaasuki, Lord Shiva sent His son Subrahmanya to protect them, who had just come to Kailasa after killing Taarakasura. (Subrahmanya is another name for Kartikeya). Subrahmanya assured the serpents that He would protect them. When Garuda came there, Subrahmanya and Garuda fought, and at the end Garuda stopped the battle as per Srihari’s will and, impressed by Subrahmanya’s power, went away from there.
Subrahmanya then came to the serpents, who thanked Him in return. He blessed the serpents that in future, He would be worshipped in the form of a five-headed serpent. Lord Subrahmanya instructed thus:
1. Nobody should kill the serpents without reason or just for fun, and if they do so, they would get a naaga dosha or sarpa dosha.
2. He would be worshipped as a five-hooded coiled serpent, especially in the Kukke Kshetra. That’s why today the kshetra is Kukke Subrahmanya Swamy Kshetra.
3. The people who pray to Him with devotion will be freed from sarpa dosha, bodily diseases, and will be granted healthy children.
That’s why we do Naagaaraadhana, which is worshipping of naagaas, along with Subrahmanya, as the shloka says:
शेषवासुकितक्षाख्याः कर्कोटोऽभो महांबुजः। शंखपालश्च कुलिशः इत्यष्टौ नागवर्यकाः।
SheSha, Vaasuki, takShaka, karkOTaka, padma, mahaapadma, shaMKapaala, kulisha - these naagas must be worshipped along with Subrahmanya Swamy on the day of Champa Shashti/Subrahmanya Shashti/Skanda Shashti.
Within every jiva, Bhagavan Vishnu is present. In the same way, within Subrahmanya too, Bhagavan Vishnu is present in the form of Sankarshana roopi Bhagavan Narayana. In the Naagas, He is present as Sankarshana roopi Bhagavan Narayana.
WHY DOES SUBRAHMANYA HAVE PEACOCK AS HIS VAAHANA?
This story also comes from the Skanda Purana only. Sage Kashyapa and Diti Devi had a son by the name Vajranga. This Vajranga married Varangi. There were three demons by the name Shoorapadma, Simhamukha, and Taarakasura, who were the sons of Vajranga and Varangi. Out of these, Shoorapadma was the eldest one, Simhamukha was the middle one, and Taarakasura was the third one and was the youngest. First, Taarakasura was killed by Subrahmanya.
After this, Simhamukha was like a good person, who was like Vibhishana, and used to advise his elder brother Shoorapadma about dharma. But Shoorapadma would ignore him, due to his sheer arrogance. For killing Shoorapadma, Subrahmanya came there with His devata troop. Here, this Simhamukha, unlike Vibhishana, chose to fight from the side of his brother Shoorapadma. In that war, Subrahmanya hurled His Shaktyaayudha on Simhamukha, and by that touch itself, Simhamukha was purified and hence surrendered to Subrahmanya. This Simhamukha is believed to have become the vaahana of Durga roopa of Umadevi later on.
Next, Subrahmanya fought with Shoorapadma. Seeing Subrahmanya’s power, Shoorapadma used his dark powers, but those too failed. At last, he assumed the form of a mango tree. Subrahmanya hurled his Shaktyayudha on that tree, which cut down the tree into two clean halves. But still Shoorapadma was alive in the form of the tree. The two halves of the tree transformed into a peacock and a rooster respectively. Subrahmanya accepted the peacock as his vaahana, whereas he kept the rooster on his flag. That’s why, like how Bhagavan Vishnu is known as Garudadhvaja (He has Garuda on His chariot flag), Lord Shiva is called Vrushabhadhvaja (He has a bull on His chariot flag), and Arjuna is known as Kapidhvaja (Hanumanji is on Arjuna’s chariot flag), Subrahmanya is also known as Kukkutadhvaja, which means He has Kukkuta or a rooster on His flag.
This is the story of Lord Subrahmanya as to why He is associated with serpents, and why He has a peacock as His vaahana, as per the Skanda Purana.
Hope this helps!
Jay SriRam!
SriSubrahmanya Antargata SriBhaaratiramana Mukhyaprana Antargata SriJayaa Sankarshana Abhinna ShriKrishnarpanamastu!