Soulcatchers' Aerie is a uncommon Enchantment card from The List (PLST), collector number JUD-25. Current market price: $5.18, TCGplayer market prices via Scryfall.
Whenever a Bird is put into your graveyard from the battlefield, put a feather counter on this enchantment. Bird creatures get +1/+1 for each feather counter on this enchantment.