Cheapest priced copy (Magic 2015): $0.35 at Card Kingdom, near mint, their price list as of .
Brood Keeper 
Creature — Human Shaman · 2/3 · Uncommon · Magic 2015 · #132
Whenever an Aura becomes attached to this creature, create a 2/2 red Dragon creature token with flying. It has "{R}: This creature gets +1/+0 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 |
|---|---|---|---|---|
| Magic 2015 | 132 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 18 July 2014Brood Keeper’s ability triggers both whenever an Aura enters the battlefield attached to Brood Keeper and whenever an Aura on the battlefield attached to a different object becomes attached to Brood Keeper.
- 18 July 2014If an Aura becomes attached to Brood Keeper that causes another player to gain control of it, that player will control the triggered ability that creates a Dragon.