Centaur Garden is a uncommon Land card from World Championship Decks 2003 (WC03), collector number dh316. Current market price: $0.25, TCGplayer market prices via Scryfall.
{T}: Add {G}. This land deals 1 damage to you. Threshold — {G}, {T}, Sacrifice this land: Target creature gets +3/+3 until end of turn. Activate only if there are seven or more cards in your graveyard.