Draugr Necromancer is a rare Snow Creature — Zombie Cleric card from Kaldheim (KHM), collector number 86. Current market price: $0.27 (foil $0.36), TCGplayer market prices via Scryfall.
If a nontoken creature an opponent controls would die, exile that card with an ice counter on it instead. You may cast spells from among cards in exile your opponents own with ice counters on them, and you may spend mana from snow sources as though it were mana of any color to cast those spells.