Falkenrath Gorger is a rare Creature — Vampire Berserker card from Shadows over Innistrad (SOI), collector number 155. Current market price: $0.25 (foil $0.55), TCGplayer market prices via Scryfall.
Each Vampire creature card you own that isn't on the battlefield has madness. The madness cost is equal to its mana cost. (If you discard a card with madness, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)