Lord Hayagreeva*

Hayagreeva (Hayavadhana or Hayagriva), the lesser known Vishnu Avatar, The Horse Faced God
He is the ocean of knowledge, Wisdom, where Brahma & Goddess Saraswathi risides. He is the Four form of Veda, viz. Rg, Yajur, Sama and Atharva Vedas. From the Eternal abode, Lord Sri Maha Vishnu who creates the life & world from His Lotus throne, He who is everywhere. It was Madhu & Kaitibha the two demons are associated with the true Lord, The Brahmma & Vishnu.

Kaitibha & Madhu who are known to have infamously stolen the Vedas when at the time the worlds were being created. The vedas, the sookshama or the Secrets of the three worlds & the root of all knowledge, carrying the essence of living had to be retrieved from the demons known as Asuras. Fearing greater loss, the Devas pleaded with the Goddess who directed them towards Sri Maha Vishnu to retrieve the Vedas. In pure whiteness, dressed in blue, Lord Vishnu descended onto the earth in the form of Hayagriva, human by nature but horse headed in form, to fight the demons and destroy them.

In Sakta tradition, Hayagriva is also the name of a demon who was the son of Kashyapa Prajapati. He did severe penance and won the favor of Goddess Durga, and asked for a boon that he should be killed only by another Hayagriva. This almost made him invincible and he began to harass the Devas. The Devas turned to Vishnu for aid, who despite a long struggle was unable to kill him. Vishnu returned to Vaikuntham and started severe penance in padmasana with his head supported by his bow. The Devas went back to request him again but were unable to shake him out of his meditation. They tried to break his deep concentration with the help of termites gnawing at the string of the bow, but the snapping of the bow resulted in the string lashing out with such force that Vishnu's head was severed from his body. It was now that Devi revealed the boon of the demon Hayagriva to the devas and told them to have Vishnu's head replaced with that of a pure white horse, making him another Hayagriva, in order to kill the demon...

Hayagriva is depicted with 4 armed, carrying a Conch & Wheel known as Shanka and chakra in His two hands, a rosary (aksha-mala) in the third and his fourth is in the vyakhya mudra. He is also found holding the vedas in some occasions. Hayagreeva is associated with the purity of knowledge and is represented in the same way as Saraswati. White is a symbolism of purity that is depicted in the "white horse" face he adorns.

In the Sri Vaishnavite tradition, Swami Sri Vedanta Desika (born in 1317 A.D. in Thoopul near Kanchipuram) is considered to be the incarnation of theghanta (bell) of the Lord of the Seven Hills, The Tirupati. He was a child prodigy who had risen to the status of "Acharya" at the age of 27. On initiation into the realm of the Garuda mantra, among his all Stotra, Swami Desikan went to Thiruvahindrapuram and began chanting. Pleased with his devotion, Garuda initiated him into the Hayagriva Mantra, encompassing all knowledge. Lord Hayagriva appeared to Desika and presented him an idol of Himself, hence all temples dedicated to Desika have an idol of Hayagriva installed near him. Thiruvahindrapuram has one of the most ancient temples dedicated to Lord Sri Hayagriva.
The rough English phonetic version of the Hayagriva stotra, the first two stanzas of the Shloka is given below:

Njaananandamayam Devam , Nirmalam Spadikakrutham |
Aadaram Sarva Vidhyaanaam, Hayagreevam Upaasmahe ||
Vidyaarambam (the first step of learning) begins with a prayer to Sri Hayagreeva, praising him as the presiding deity for all knowledge. May He grant us the power to imbibe this knowledge & wisdom we seek with the recitation of this mantra.