Tundra Fumarole is a rare Snow Sorcery card from Kaldheim Promos (PKHM), collector number 156p. Current market price: $0.25 (foil $0.28), TCGplayer market prices via Scryfall.
Tundra Fumarole deals 4 damage to target creature or planeswalker. Add {C} for each {S} spent to cast this spell. Until end of turn, you don't lose this mana as steps and phases end. ({S} is mana from a snow source.)