Cheapest priced copy (Eventide): $0.35 at Card Kingdom, near mint, their price list as of .
Duergar Mine-Captain 
Creature — Dwarf Soldier · 2/1 · Uncommon · Eventide · #138
{1}{R/W}, {Q}: Attacking creatures get +1/+0 until end of turn. ({Q} is the untap symbol.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Eventide | 138 | Uncommon | $0.35 | $0.99 |
4 rulings from Wizards of the Coast
- 1 August 2008The “summoning sickness” rule applies to {Q}. If a creature with an {Q} ability hasn’t been under your control since your most recent turn began, you can’t activate that ability. Ignore this rule if the creature also has haste.
- 1 August 2008When you activate an {Q} ability, you untap the creature with that ability as a cost. The untap can’t be responded to. (The actual ability can be responded to, of course.)
- 1 August 2008If the permanent is already untapped, you can’t activate its {Q} ability. That’s because you can’t pay the “Untap this permanent” cost.
- 1 August 2008This ability affects only creatures that are attacking at the time it resolves. It won’t affect creatures that attack later in the turn.