Cheapest priced copy (Mirage): $0.35 at Card Kingdom, near mint, their price list as of .
Dirtwater Wraith 
Creature — Wraith · 1/3 · Common · Mirage · #117
Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{B}: This creature gets +1/+0 until end of turn.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern