Cheapest priced copy (The Lost Caverns of Ixalan): $0.35 at Card Kingdom, near mint, their price list as of .
Bat Colony 
Enchantment · Uncommon · The Lost Caverns of Ixalan · #5
When this enchantment enters, create a 1/1 black Bat creature token with flying for each mana from a Cave spent to cast it.
Whenever a Cave you control enters, put a +1/+1 counter on target creature you control.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The Lost Caverns of Ixalan | 5 | Uncommon | $0.35 | $0.49 |