Graf Rats is a uncommon Creature — Rat card from Innistrad Remastered (INR), collector number 113. Current market price: $0.24 (foil $0.34), TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, if you both own and control this creature and a creature named Midnight Scavengers, exile them, then meld them into Chittering Host.