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

• Rarity: Rare
• Finish: Normal
• Artist: Svetlin Velinov
• Card Text:
  Whenever Sludge Monster enters the battlefield or attacks, put a slime counter on up to one other target creature.
  Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.