Your search for "Implement of Ferocity 157" revealed the following:
Implement of Ferocity (AER) from Aether Revolt, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Jason Kang Card Text:G, Sacrifice Implement of Ferocity: Put a +1/+1 counter on target creature. Activate this ability only any time you could...
Implement of Ferocity (Foil) (AER) from Aether Revolt, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Jason Kang Card Text:G, Sacrifice Implement of Ferocity: Put a +1/+1 counter on target creature. Activate this ability only any time you...