Quandrix Pledgemage is a common Creature — Merfolk Druid card from Strixhaven: School of Mages (STX), collector number 219. Current market price: $0.17 (foil $0.29), TCGplayer market prices via Scryfall.
Magecraft — Whenever you cast or copy an instant or sorcery spell, put a +1/+1 counter on this creature.