Cubwarden is a rare Creature — Cat card from Ikoria: Lair of Behemoths (IKO), collector number 7. Current market price: $0.36 (foil $0.37), TCGplayer market prices via Scryfall.
Mutate {2}{W}{W} (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.) Lifelink Whenever this creature mutates, create two 1/1 white Cat creature tokens with lifelink.