Gamekeeper is a uncommon Creature — Elf card from Urza's Destiny (UDS), collector number 106. Current market price: $0.32 (foil $22.70), TCGplayer market prices via Scryfall.
When this creature dies, you may exile it. If you do, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and put all other cards revealed this way into your graveyard.