Skithiryx, the Blight Dragon [The List] Kaya Nightmare's power and toughness are

Nightmare's power and toughness are each equal to the number of Swamps you control

Set: Judge Gift Cards 2004 Type: Creature — Human Druid Rarity: Rare Cost: {1}{G} {G}

"The City in the Sea"

Set: Collectors’ Edition Type: Creature — Giant Rarity: Rare Cost: {4}{R} Trample

Skithiryx, the Blight Dragon [The List] Kaya Nightmare's power and toughness areSet: The List Type: Legendary Creature Phyrexian Dragon Skeleton Rarity: Mythic Cost: {3}{B}{B} Flying Infect (This creature deals damage to creatures in the form of 1 1 counters and to players in the form of poison counters.) {B}: Skithiryx, the Blight Dragon gains haste until end of turn. {B}{B}: Regenerate Skithiryx.