Cheapest priced copy (Commander's Arsenal Oversized): $2.49 at Card Kingdom, foil, near mint, their price list as of .
Karrthus, Tyrant of Jund 
Legendary Creature — Dragon · 7/7 · Mythic · Double Masters · #205
Flying, haste
When Karrthus enters, gain control of all Dragons, then untap all Dragons.
Other Dragon creatures you control have haste.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
5 printings · $2.49 to $32.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 205 | Mythic | $6.99 | $10.99 |
| Alara Reborn | 117 | Mythic | $7.49 | $32.99 |
| Commander's Arsenal Oversized | 7 | Mythic | — | $2.49 |
| The List | ARB-117 | Mythic | — | $5.49 |
| Secret Lair Drop | 1250 | Mythic | $11.99 | $15.99 |
2 rulings from Wizards of the Coast
- 7 August 2020When the triggered ability resolves, you'll untap all Dragons, including the ones you already control.
- 7 August 2020The control-change effect of Karrthus's triggered ability lasts indefinitely. It doesn't wear off during the cleanup step, and it doesn't expire if Karrthus leaves the battlefield. In a multiplayer game, it does expire if you leave the game.