Your search for "Most Valuable Slayer 144" revealed the following:
Most Valuable Slayer (Foil) (DSK) from Duskmourn: House of Horror, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Patrik Hell Card Text:Whenever you attack, target attacking creature gets +1/+0 and gains first strike until end of turn.
Most Valuable Slayer (DSK) from Duskmourn: House of Horror, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Patrik Hell Card Text:Whenever you attack, target attacking creature gets +1/+0 and gains first strike until end of turn.