Cheapest priced copy (Hour of Devastation): $0.49 at Card Kingdom, near mint, their price list as of .
Apocalypse Demon 
Creature — Demon · */* · Rare · Hour of Devastation · #58
Flying
Apocalypse Demon's power and toughness are each equal to the number of cards in your graveyard.
At the beginning of your upkeep, tap this creature unless you sacrifice another creature.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.49 to $2.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Hour of Devastation | 58 | Rare | $0.49 | $0.99 |
| Hour of Devastation Promos | 58s | Rare | — | $2.79 |
One ruling from Wizards of the Coast
- 14 July 2017The ability that defines Apocalypse Demon's power and toughness works in all zones, not just the battlefield.