Cheapest priced copy (Shards of Alara): $0.49 at Card Kingdom, near mint, their price list as of .
Archdemon of Unx 
Creature — Demon · 6/6 · Rare · Shards of Alara · #64
Flying, trample
At the beginning of your upkeep, sacrifice a non-Zombie creature, then create a 2/2 black Zombie creature token.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Shards of Alara | 64 | Rare | $0.49 | $0.79 |
2 rulings from Wizards of the Coast
- 1 October 2008If you somehow control no non-Zombie creatures when the triggered ability resolves, you won’t have to sacrifice anything. You’ll still get a Zombie token.
- 1 October 2008If Archdemon of Unx is the only non-Zombie creature you control when the triggered ability resolves, you’ll have to sacrifice it. You’ll still get a Zombie token.