Boreal Centaur is a common Snow Creature — Centaur Warrior card from Coldsnap (CSP), collector number 104. Current market price: $0.23 (foil $0.62), TCGplayer market prices via Scryfall.
{S}: This creature gets +1/+1 until end of turn. Activate only once each turn. ({S} can be paid with one mana from a snow source.)