Raven Guild Master is a rare Creature — Human Wizard Mutant card from Scourge (SCG), collector number 47. Current market price: $1.06 (foil $13.44), TCGplayer market prices via Scryfall.
Whenever this creature deals combat damage to a player, that player exiles the top ten cards of their library. Morph {2}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)