Nightmare

Creature - Nightmare Horse X/X, 5B (6)
Flying
Nightmare's power and toughness are each equal to the number of Swamps you control.¹
The Nightmare arises from its lair in the swamps. As the poisoned land spreads, so does the Nightmare's rage and terrifying strength.
Illus. Melissa Benson

Gatherer Card Rulings [Nov 2009]

• 4/1/2008: If you control 0 swamps, then the Nightmare has 0 toughness and will be put into its owner's graveyard as a state-based effect right before the next player gains priority.

Format Legality	Legal in Vintage, Legacy, Extended, Standard
Printings (12/69)	Magic 2010 (Rare) Tenth Edition (Rare) Core Set - Ninth Edition (Rare) Core Set - Eighth Edition (Rare) Seventh Edition (Rare) Fourth Edition (Rare) → View All