Wolf of Devil's Breach is a mythic Creature — Elemental Wolf card from Shadows over Innistrad Promos (PSOI), collector number 192s. Current market price: — (foil $1.79), TCGplayer market prices via Scryfall.
Whenever this creature attacks, you may pay {1}{R} and discard a card. If you do, this creature deals damage to target creature or planeswalker equal to the discarded card's mana value.