If the creature has 0 power, this ability has no effect.
2008-04-01
The creature's power is checked as this ability resolves. If the creature has left the battlefield, use its last known information.
2008-04-01
If the creature has 1 power, this ability lets you look at the top card of your library, then you'll have to leave it there.
Whenever a creature you control enters, you may look at the top X cards of your library, where X is that creature's power. If you do, put one of those cards on top of your library and the rest on the bottom of your library in any order.