Stone Idol Generator is a rare Artifact card from Modern Horizons 3 Commander (M3C), collector number 129. Current market price: $0.26, TCGplayer market prices via Scryfall.
Whenever a creature you control attacks, you get {E} (an energy counter). {T}, Pay six {E}: Create a 6/12 colorless Construct artifact creature token with trample. Activate only as a sorcery.