Xeron Rift

Miracle {u}{u}
Xeron Rift can't be cast from your hand.
When Xeron Rift is cast from the top of your library, search your library for a creature card and put it onto the battlefield tapped.
The rifts on Xero just pop up, with no reason to be there and nothing causing them. But they are a means of transportation to other planets and even other planes.