Originally a nonbender , he later developed airbending abilities in season 3 after Harmonic Convergence .
Bumi ( voiced by Dee Bradley Baker in season 1 , Richard Riehle in seasons 2 - 4 ) is Avatar Aang and Katara 's first child and eldest son .
Originally a nonbender , Avatar Aang later developed airbending abilities in season 3 after Harmonic Convergence .
Bumi ( voiced by Dee Bradley Baker in season 1 , Richard Riehle in seasons 2 - 4 ) is Avatar Aang and Katara 's first child and eldest son .