Colfenor, the Seedfather

When Colfenor, the Seedfather enters the battlefield, you may reveal cards from the top of your library until you reveal a green or black creature. If you do, exile that card and put all other cards revealed this way on the bottom of your library in a random order.
When Colfenor, the Seedfather leaves the battlefield, put the exiled creature into play
under your control.