One with Nature is a uncommon Enchantment — Aura card from Scourge (SCG), collector number 125. Current market price: $3.15 (foil $16.86), TCGplayer market prices via Scryfall.
Enchant creature Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.