Mouth of Ronom is a uncommon Snow Land card from Coldsnap (CSP), collector number 148. Current market price: $1.11 (foil $12.68), TCGplayer market prices via Scryfall.
{T}: Add {C}. {4}{S}, {T}, Sacrifice this land: It deals 4 damage to target creature. ({S} can be paid with one mana from a snow source.)