Firebending Student is a rare Creature — Human Monk card from Avatar: The Last Airbender Promos (PTLA), collector number 139s. Current market price: — (foil $5.81), TCGplayer market prices via Scryfall.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Firebending X, where X is this creature's power. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)