Puzzlebox of Summoning

When you cast Puzzlebox of Summoning, put
the top four cards of your library face-down onto
the battlefield.
At the beginning of your upkeep, target player reveals target face-down card you control. If it is
a creature card, put it onto the battlefield tapped. Otherwise, sacrifice Puzzlebox of Summoning,
the revealed card, and all other face-down permanents.