Overgrown Tomb is a rare Land — Swamp Forest card from Guilds of Ravnica Promos (PGRN), collector number 253p. Current market price: $9.91 (foil $18.05), 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.