Magmaroth is a uncommon Creature — Elemental card from Hour of Devastation (HOU), collector number 102. Current market price: $0.07 (foil $0.32), TCGplayer market prices via Scryfall.
At the beginning of your upkeep, put a -1/-1 counter on this creature. Whenever you cast a noncreature spell, remove a -1/-1 counter from this creature.