Cheapest priced copy (Duel Decks: Nissa vs. Ob Nixilis): $0.35 at Card Kingdom, near mint, their price list as of .
Blistergrub 
Creature — Phyrexian Horror · 2/2 · Common · The List · #DDR-40
Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When this creature dies, each opponent loses 2 life.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Nissa vs. Ob Nixilis | 40 | Common | $0.35 | — |
| The List | DDR-40 | Common | $0.35 | — |
| Scars of Mirrodin | 56 | Common | $0.35 | $0.49 |