Glowstone Recluse is a uncommon Creature — Spider card from Ikoria: Lair of Behemoths (IKO), collector number 296. Current market price: $0.30 (foil $0.49), TCGplayer market prices via Scryfall.
Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Reach Whenever this creature mutates, put two +1/+1 counters on it.