Cheapest priced copy (Theros Beyond Death): $0.35 at Card Kingdom, near mint, their price list as of .
Nyx Herald 
Enchantment Creature — Centaur Shaman · 2/3 · Uncommon · Theros Beyond Death · #189
At the beginning of combat on your turn, target enchanted creature or enchantment creature you control gets +1/+1 and gains trample until end of turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Theros Beyond Death | 189 | Uncommon | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 24 January 2020Once Nyx Herald’s ability resolves, the creature keeps +1/+1 and trample even if it stops being enchanted later in the turn (or, in some unusual cases, stops being an enchantment).