Vivien, Nature's Advocate

Reach, haste
After blockers are declared, if Vivien, Nature's Advocate is unblocked choose one- you may put a creature card from your hand on to the battlefield tapped and attacking, or reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield tapped and attacking and the rest are shuffled into your library. Untap Vivien, Nature's Advocate, she deals no combat damage this turn.