Crater Elemental is a rare Creature — Elemental card from Dragons of Tarkir (DTK), collector number 132. Current market price: $0.21 (foil $0.25), TCGplayer market prices via Scryfall.
{R}, {T}, Sacrifice this creature: It deals 4 damage to target creature. Formidable — {2}{R}: This creature has base power 8 until end of turn. Activate only if creatures you control have total power 8 or greater.