Hanumaan is the son of god Vaayu. He is the strongest . He is a principal person in the epic Raamaayanam. He is also the deity as widely worshipped as Raama himself.His role in Raamaayanam is pivotal.
But, his part is very little in the Mahaabhaaratham. He appears in the story first in Aaranya parva, when Bheema met him on his errand for the divine Sougandhika flowers. On that occasion, Hanumaan promised to be present on Arjuna's banner with his terrific follower-deities.
Again, he appears in the story many years later, in Dvaaraka, challenging the proud Arjuna to build a bridge on the sea with arrows as Raama did with stones.
Hanumman is the disciple of Sun god. He is a matchless musician too. People believe that he dispels the ghosts and fears from the ghosts and demons.