Cheapest priced copy (Duel Decks: Venser vs. Koth): $0.35 at Card Kingdom, near mint, their price list as of .
Slith Strider 
Creature — Slith · 1/1 · Uncommon · Mirrodin · #50
Whenever this creature becomes blocked, draw a card.
Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Venser vs. Koth | 9 | Uncommon | $0.35 | — |
| Mirrodin | 50 | Uncommon | $0.35 | $0.49 |