Stonebinder's Familiar is a uncommon Creature — Spirit Dog card from Strixhaven: School of Mages (STX), collector number 31. Current market price: $0.27 (foil $0.20), TCGplayer market prices via Scryfall.
Whenever one or more cards are put into exile during your turn, put a +1/+1 counter on this creature. This ability triggers only once each turn.