His name is actually Iravat and hes the eldest son of Arjuna, possibly the second eldest child of the Pandava clan (the eldest was Ghatotkatcha).
He spent his childhood in the care of his mother, his uncle (Ulupi’s brother) hated his father (Arjuna) so Iravat was abandoned by him.
Below is a quote:
Abandoned by his wicked uncle from hatred of Partha, he grew up in the region of the Nagas, protected by his mother. And he was handsome and endued with great strength, possessed of diverse accomplishments, and of prowess incapable of being baffled.
Hearing that Arjuna had gone to the region of Indra, he speedily went thither. And the mighty-armed Iravat, possessed of prowess incapable of being baffled, approaching his sire, saluted him duly, standing before him with joined hands. And he introduced himself to the high-souled Arjuna, saying,
‘I am Iravat. blessed be thou, and I am thy son, O lord’.
And he reminded Arjuna of all the circumstances connected with the latter’s meeting with his mother. And thereupon the son of Pandu recollected all those circumstances exactly as they happened. Embracing his son then who resembled himself in accomplishments, Partha, in Indra’s abode, was filled with joy.
The mighty-armed Iravat then, O king, in the celestial regions was, O Bharata, joyfully commanded by Arjuna, with regard to his own business, (in these words), ‘When the battle takes place, assistance should be rendered by thee’. Saying ‘Yes’, O lord, he went away. And now at the time of battle he presented himself.
Maha-bharata, Bhishma Parva, Bhagavat-Gita Parva: Section XCI
#iravan #iravat #arjuna