Cheapest priced copy (Commander Masters): $32.99 at Card Kingdom, near mint, their price list as of .
Ulamog, the Ceaseless Hunger 
Legendary Creature — Eldrazi · 10/10 · Mythic · Battle for Zendikar · #15
When you cast this spell, exile two target permanents.
Indestructible
Whenever Ulamog attacks, defending player exiles the top twenty cards of their library.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
7 printings · $32.99 to $89.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battle for Zendikar | 15 | Mythic | $34.99 | $54.99 |
| Commander Masters | 5 | Mythic | $32.99 | $44.99 |
| Commander Masters | 454 | Mythic | — | — |
| Commander Masters | 670 | Mythic | $34.99 | $44.99 |
| Commander Masters | 1059 | Mythic | — | $54.99 |
| Battle for Zendikar Promos | 15s | Mythic | — | $89.99 |
| The List | BFZ-15 | Mythic | — | — |
3 rulings from Wizards of the Coast
- 25 August 2015If the player has less than twenty cards in their library, exile all of them. That player won't lose the game until they have to draw a card from an empty library.
- 25 August 2015Cards exiled by Ulamog's first and third abilities are exiled face up.
- 25 August 2015Ulamog's first ability resolves independently of Ulamog once they've both been put on the stack. If Ulamog is countered, that triggered ability will still resolve. That triggered ability will always resolve before Ulamog does.