Cheapest priced copy (Dragon's Maze): $0.35 at Card Kingdom, near mint, their price list as of .
Boros Mastiff 
Creature — Dog · 2/2 · Common · Dragon's Maze · #1
Battalion — Whenever this creature and at least two other creatures attack, this creature gains lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dragon's Maze | 1 | Common | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 15 April 2013The effects of battalion abilities vary from card to card. Read each card carefully.
- 15 April 2013Once a battalion ability has triggered, it doesn't matter how many creatures are still attacking when that ability resolves.
- 12 January 2024The three attacking creatures don't have to be attacking the same player, planeswalker, or battle.