(The Y in this name is pronounced like 'y' in 'you'. In the alternative spelling, the SH is pronouced like one between 's' in 'sip' and 'sh' in 'ship'. )
Once there was a demon named Hayagreeva. Vishnu killed him. Again, once Vishnu was tired with the task of killing many demons. He felt asleep in the shade of a tree, resting his chin on the tip of his bow. As he did not wake up for many years, the gods felt uncomfortable in his absence. Afraid of waking up Vishnu themselves, they sent a small insect to snap the string of the bow, to cause a jerk to make him awake. The insect bit off the string and in an instant, the tightly held bow relaxed and the cut-off string flashed off through Vishnu's throat, severing his head from his body. All the gods fixed a horse head to Vishnu and named him Hayagreeva (haya=horse, greeva=neck or head).
It is in this form that Vishnu is worshipped as donor of knowledge and education. Many scholars worship this form for excellence in knowledge. Also, Vishnu restored the vedas from Somaka in this form and awarded them to Brahma.
"After praying to Naaraayana, Nara, Sarasvathi and Vyaasa, then one should read the Jayam."
DEDICATED TO MY DEAR NIECE VYSHNAVI KRISHNA