Karrthus, Tyrant of Jund is a mythic Legendary Creature — Dragon card from Double Masters (2XM), collector number 205. Current market price: $4.74 (foil $7.06), TCGplayer market prices via Scryfall.
Flying, haste When Karrthus enters, gain control of all Dragons, then untap all Dragons. Other Dragon creatures you control have haste.