Necropanther is a uncommon Creature — Cat Nightmare card from Ikoria: Lair of Behemoths (IKO), collector number 196. Current market price: $0.15 (foil $0.27), TCGplayer market prices via Scryfall.
Mutate {2}{W/B}{W/B} (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.) Whenever this creature mutates, return target creature card with mana value 3 or less from your graveyard to the battlefield.