Cheapest priced copy (Dissension): $0.39 at Card Kingdom, near mint, their price list as of .
Nightcreep 
Instant · Uncommon · Dissension · #49
Until end of turn, all creatures become black and all lands become Swamps.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.39 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dissension | 49 | Uncommon | $0.39 | $3.49 |
4 rulings from Wizards of the Coast
- 1 May 2006A land or creature that enters after Nightcreep resolves won't be affected by it.
- 1 May 2006This effect overwrites all lands' land types. Lands will be Swamps instead of any other land types. This won't affect a land's supertypes (such as basic or legendary). Lands will lose their normal abilities and have the ability "{T}: Add {B}" instead.
- 1 May 2006If a permanent is both a creature and a land, Nightcreep replaces all of its land types with Swamp, but it doesn't affect its creature types. The creature land loses all abilities generated by its rules text and its previous land types but retains any abilities granted to it by other effects. For example, an animated Blinkmoth Nexus becomes a black creature land with the land subtype Swamp whose only abilities are flying and "{T}: Add {B}."
- 1 May 2006This effect overwrites all creatures' colors. Creatures will be black instead of any other color or colors.