Oracle Text

When Gamekeeper 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.

Card Rulings

10/4/2004 If you have no creature cards in your library, all the cards from your library end up in your graveyard and you do not get to put a creature onto the battlefield.
10/4/2004 Exiling this card is optional.