Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.) Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.
Near Mint - $0.20
Lightly Played - $0.10
Moderately Played - $0.10
Heavily Played - $0.10
Damaged - $0.10
Near Mint Spanish - $0.20
Lightly Played Spanish - $0.10
Moderately Played Spanish - $0.10
Heavily Played Spanish - $0.10
Damaged Spanish - $0.10