Valakut, the Molten Pinnacle is a rare Land card from Secret Lair Promo (SLP), collector number 14. Current market price: $41.43 (foil $334.09), TCGplayer market prices via Scryfall.
This land enters tapped. Whenever a Mountain you control enters, if you control at least five other Mountains, you may have this land deal 3 damage to any target. {T}: Add {R}.