Katara, Seeking Revenge is a uncommon Legendary Creature — Human Warrior Ally card from Avatar: The Last Airbender Eternal (TLE), collector number 148. Current market price: $0.15 (foil $1.05), TCGplayer market prices via Scryfall.
As an additional cost to cast this spell, you may waterbend {2}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.) When Katara enters, draw a card, then discard a card unless her additional cost was paid. Katara gets +1/+1 for each Lesson card in your graveyard.