Cheapest priced copy (Commander 2015): $0.35 at Card Kingdom, near mint, their price list as of .
Grave Peril 
Enchantment · Common · Future Sight · #67
When a nonblack creature enters, sacrifice this enchantment. If you do, destroy that creature.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2015 | 128 | Common | $0.35 | — |
| Future Sight | 67 | Common | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 1 May 2007If multiple nonblack creatures enter at the same time, Grave Peril will destroy only one of them. Grave Peril's ability will trigger multiple times, but only the first one to resolve will do anything.
- 1 May 2007If a nonblack creature enters and Grave Peril triggers, then another nonblack creature enters, Grave Peril will trigger again and destroy only the last creature to enter.
- 1 May 2007This ability is not optional.