Lord Hanuman in Mahabharat

Hanumanji has been mentioned in another great epic, The Mahabharat.

Being a chiranjeevi, he has lived through all ages, singing the praises of Lord Rama. When the Pandavas were in the forest, Darupadi requested Bhima for the Saugandika flower of heavenly fragrance. On this way to get this flower, Bhima encountered a monkey lying in the middle of his path. Angered by this delay in his mission, Bhima crossly asked the 'ape' to clear the path and let him pass.

The monkey slowly looked at Bhima, and requested him "I am very old and can't even move, just push my tail to one side and you move on ahead"

Bhima was full of contempt for the monkey, but tried to push the tail away with his mace (Gadha) but it wouldn't budge. Try as he would, he could not get the tail to shift. It was then that Bhima realized that this was no ordinary monkey and with folded hands begged his pardon.

On another occasion, when Arjun met Hanumantha, he said "Rama need not have asked the monkeys to build a bridge to Lanka. If it were me, I would simply have made a bridge with my arrows"

Hanumanji replied that a bridge of Arjun's arrows would not be strong enough to carry his weight let alone the whole Vanar army.

This developed into a challenge. It was decided that if Hanumanji managed to walk across the bridge then Arjun would have to jump into the fire, and if Arjun won then Hanumanji would have to bless Arjun during the war with the Kauravs by adorning his flag.

Arjun built a bridge with his arrows. No sooner did Hanumantha step one foot on it than it broke into pieces. Arjun got ready to jump in to the fire.
At that very minute, Lord Krishna appeared and asked for the bridge to be re-built. When it was done, he touched it with his divine hands as if to test it, and then asked Hanumanji to step onto it. This time around, even when Hanumanji danced heavily on the bridge, it did not break. Hanumantha kept his promise and entered Arjun's banner.