夜(よる)の咆(ほう)哮(こう)獣(じゅう)

Bestow (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.)

This creature and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.