Cheapest priced copy (Battle for Zendikar): $0.49 at Card Kingdom, near mint, their price list as of .
Angelic Captain 
Creature — Angel Ally · 4/3 · Rare · Battle for Zendikar · #208
Flying
Whenever this creature attacks, it gets +1/+1 until end of turn for each other attacking Ally.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.49 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battle for Zendikar | 208 | Rare | $0.49 | $0.49 |
| Battle for Zendikar Promos | 208s | Rare | — | $1.49 |
2 rulings from Wizards of the Coast
- 25 August 2015Once the ability resolves, the bonus won’t change later in the turn, even if the number of other attacking Allies does.
- 25 August 2015Count the number of other attacking Allies as the ability resolves to determine the size of the bonus. Attacking Allies controlled by a teammate will count toward this total.