Traitor's Roar is a common Sorcery card from Shadowmoor (SHM), collector number 200. Current market price: $0.15 (foil $0.63), TCGplayer market prices via Scryfall.
Tap target untapped creature. It deals damage equal to its power to its controller. Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)