Nightmare [Revised Edition] Zendikar Prerelease Promos whenever an attacking creature deals

whenever an attacking creature deals combat damage to you

Whenever you cast a creature spell

look at the top ten cards of your library

−6: Create a white Avatar creature token

When this creature becomes the target of a spell or ability an opponent controls

Nightmare [Revised Edition] Zendikar Prerelease Promos whenever an attacking creature dealsSet: Revised Edition Type: Creature Nightmare Horse Rarity: Rare Cost: {5}{B} Flying (This creature can't be blocked except by creatures with flying or reach.) Nightmare's power and toughness are each equal to the number of Swamps you control. The Nightmare arises from its lair in the swamps. As the poisoned land spreads, so does the Nightmare's rage and terrifying strength.