Cheapest priced copy (Mirrodin Besieged): $0.35 at Card Kingdom, near mint, their price list as of .
Caustic Hound 
Creature — Phyrexian Dog · 4/4 · Common · Mirrodin Besieged · #40
When this creature dies, each player loses 4 life.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin Besieged | 40 | Common | $0.35 | $0.49 |