Katara, Water Tribe's Hope is a rare Legendary Creature — Human Warrior Ally card from Avatar: The Last Airbender (TLA), collector number 231. Current market price: $0.54 (foil $0.68), TCGplayer market prices via Scryfall.
Vigilance When Katara enters, create a 1/1 white Ally creature token. Waterbend {X}: Creatures you control have base power and toughness X/X until end of turn. X can't be 0. Activate only during your turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)