Sorcery, 4G (5)
Uncommon
Put a 1/2 green Spider creature token with reach onto the battlefield for each creature card in your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)
Illus. Daniel Ljunggren

9/22/2011: The number of creature cards in your graveyard is counted when Spider Spawning resolves.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Standard (Type 2)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern