Witch-Maw Nephilim is a rare Creature — Nephilim card from The List (PLST), collector number GPT-138. Current market price: $2.69, TCGplayer market prices via Scryfall.
Whenever you cast a spell, you may put two +1/+1 counters on this creature. Whenever this creature attacks, it gains trample until end of turn if its power is 10 or greater.