Witchstalker is a rare Creature — Wolf card from Magic 2014 (M14), collector number 202. Current market price: $0.29 (foil $0.56), TCGplayer market prices via Scryfall.
Hexproof (This creature can't be the target of spells or abilities your opponents control.) Whenever an opponent casts a blue or black spell during your turn, put a +1/+1 counter on this creature.