Hanuman was born to Anjani, a female Apsara and Vayu the Wind God. He was blessed with supreme intelligence, strength and divine powers. As a baby, Hanuman was quite naughty and used his powers to pester the saints living in the nearby forest. Once when he was hungry he leapt to catch the sun thinking it was a fruit.
On the insistence of Vayu, Indra and the other God's came together to bless baby Hanuman of immortal life. Blessed with divine powers Hanuman grew up to be powerful and mighty. No harm could befall him from any weapons, fire and water. He could overcome death and above all he could transform his body to take the smallest form or attain the biggest form of life.
He helped Lord Ram and Laxman in their search for Sita. Hanuman with his super powers helped Lord Ram and Laxman defeat Ravan and secure the release of Sita. Seeing his devotion and love towards him, Lord Ram blessed Hanuman with the boon of immortality.