Overgrown Tomb is a rare Land — Swamp Forest card from Lorwyn Eclipsed Promos (PECL), collector number 266p. Current market price: $8.89 (foil $10.01), TCGplayer market prices via Scryfall.
({T}: Add {B} or {G}.) As this land enters, you may pay 2 life. If you don't, it enters tapped.