Nighthowler (CLB) from Commander Legends: Battle for Baldur's Gate, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Nils Hamm
• Card Text:
  Bestow 2BB (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.