Cheapest priced copy (Prophecy): $0.35 at Card Kingdom, near mint, their price list as of .
Hollow Warrior 
Artifact Creature — Golem Warrior · 4/4 · Uncommon · Prophecy · #138
This creature can't attack or block unless you tap an untapped creature you control not declared as an attacking or blocking creature this combat. (This cost is paid as attackers or blockers are declared.)
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Prophecy | 138 | Uncommon | $0.35 | $0.99 |
One ruling from Wizards of the Coast
- 4 October 2004This card can’t tap itself to allow itself to attack or block. You have to tap a different creature which is not being declared as an attacker or blocker.