Cheapest priced copy (Fourth Edition): $0.35 at Card Kingdom, near mint, their price list as of .
Marsh Viper 
Creature — Snake · 1/2 · Common · Fifth Edition · #315
Whenever this creature deals damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
5 printings · $0.35 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Fourth Edition Foreign Black Border | 263 | Common | — | — |
| Fourth Edition | 263 | Common | $0.35 | — |
| Fifth Edition | 315 | Common | $0.35 | — |
| The Dark | 81 | Common | $0.35 | — |
| Renaissance | 149 | Common | — | — |