Shadow Word: Ruin is a Priest spell card (rarity: epic) that belongs to the current "Core" set. The artist of this card was Ben Olson, who also made 10 other artworks for Hearthstone.
The card costs 4 mana and its card text reads: "Destroy all minions with 5 or more Attack."
The flavor text of the card is the following: Discovered by a worgen priest after a giant spilled a drink on her new white robes.