Hanuman has the names Hanuman, Maruti, Pavanakumara, Vayusutra, Anjaneya, Kesarinandana, Mahavira, Bajarangi, Sankatamocana. He is of the now extinct race of varnaras, an intelligent monkey race who could read, write and talk. Hanuman was a master of the language of the demons, the pasthista language. When asked who he was, he would reply: 'I am the servant of the Lord Kosala, Sri Rama.'
Hanuman is shown kneeling with joined palms beside Rama, Lakshmana, and Sita, sometimes tearing his chest open to show Rama's image in his heart; other times flying through the air with an Himalayan peak in his hand; long haired, occasionally five-headed, hands raised in abhayahasta (blessing to remove fear), carrying club, bow, and thunderbolt. Devoted and providing devotion, compassionate yet fierce, protector and remover of obstacles, giver of prosperity and destroyer of evil. 
Hanuman is a participant in the Ramayana, the story of Sri Rama, Avatar of Vishnu, and the rescue of Sita from the clutches of Ravana, the Lord of Lanka. Hanuman appears in the Ramayana of Sage Valmiki, and the Ramacharitmanas, the retelling of the Ramayana by Tulsidas. Hanuman is Vayuputru, son of the God of the wind, Vayu. Hanuman possessed scholarship in Sanskrit, astrology, music and poetry. Authorship of Mahanataka (a dramatic play on the story of Rama in 14 Acts) is traditionally ascribed to him.
In the Oriya Mahabharatha and in the Marathi Bhavarta Ramayana, Hanuman is said to be born with a vajra loincloth (vajrakupina) symbolising his adamintine establishment in brahmacharya, the celibate state. Brahmacharya in its original and literate sense, signifies far more than celibacy or even general self-control. One who wanders and by extension lives in Brahman (a brahmacarin) is also a knower of Brahman ( a brahmajnanin). Tulsidas extolls Hanuman as the foremost among the jnanins.
The Devotion of Hanuman
At the end of the Ramayana, Sri Rama rewards Hanuman's devotion by granting him the boon of immortality. Wherever the Ramayana is chanted, there Hanuman is present.
Lord Rama Himself said to Sri Hanuman, "I am greatly indebted to you, O mighty hero! You did marvellous, superhuman deeds. You do not want anything in return. Sugriva has his kingdom restored to him. Angada has been made the crown prince. Vibhishana has become king of Lanka. But you have not asked for anything at any time. You threw away the precious garland of pearls given to you by Sita. How can I repay My debt of gratitude to you? I will always remain deeply indebted to you. I give you the boon of everlasting life. All will honour and worship you like Myself. Your murti will be placed at the door of My temple and you will be worshipped and honoured first. Whenever My stories are recited or glories sung, your glory will be sung before Mine. You will be able to do anything, even that which I will not be able to!"
Thus did Lord Rama praise Hanuman when the latter returned to Him after finding Sita in Lanka. Hanuman was not a bit elated. He fell in prostration at the holy feet of Lord Rama.
Lord Rama asked him: "O mighty hero, how did you cross the ocean?"
Hanuman humbly replied: "By the power and glory of Thy Name, my Lord."
Again the Lord asked: "How did you burn Lanka? How did you save yourself?"
And Hanuman replied: "By Thy Grace, my Lord." 
Gayatri Mantra is known to be the greatest mantra. The Rishis of the yore composed different Mantras on the same meter as that of Gayatri on different manifestations of God. Many Hindu devas have their own mantras, including a Gayatri mantra. The Gayatri Mantra is a highly revered Sanskrit mantra with origins in the Vedas. It is a verse in the vedic Gayatri metre (whence the mantra's name), consting of 24 syllables,
Tanno Hanuman Pracodayat
I salute Anjaneya, the son of Vayu, and invoke Hanuman to pray him
Notes and References
- Jouveau-Dubreuil, G., Iconography of Southern India. Paris, Librarie Orientaliste, 1937
- Lanka is not the Sri Lanka of today, but a sunken continent in the Indian Ocean, in the region of the equator. Ref, Sathya Sai Baba, Divine Discourse
- Bulke, C. The Characterisation of Hanuman in Journal of the Oriental Institute, Baroda, Vol 9, No 4, p. 400
- Sivananda, Hindu Feasts and Festivals, Divine Life Society, http://www.dlshq.org/download/hindufest.htm