Spawn of Mayhem is a mythic Creature — Demon card from Ravnica Allegiance (RNA), collector number 85. Current market price: $0.52 (foil $3.02), TCGplayer market prices via Scryfall.
Spectacle {1}{B}{B} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.) Flying, trample At the beginning of your upkeep, this creature deals 1 damage to each player. Then if you have 10 or less life, put a +1/+1 counter on this creature.