Gremlin Infestation is a uncommon Enchantment — Aura card from Aether Revolt (AER), collector number 83. Current market price: $0.04 (foil $0.40), TCGplayer market prices via Scryfall.
Enchant artifact At the beginning of your end step, this Aura deals 2 damage to enchanted artifact's controller. When enchanted artifact is put into a graveyard, create a 2/2 red Gremlin creature token.