Amplifire is a rare Creature — Elemental card from Ravnica Allegiance (RNA), collector number 92. Current market price: $0.17 (foil $0.43), TCGplayer market prices via Scryfall.
At the beginning of your upkeep, reveal cards from the top of your library until you reveal a creature card. Until your next turn, this creature's base power becomes twice that card's power and its base toughness becomes twice that card's toughness. Put the revealed cards on the bottom of your library in a random order.