The Good, The Bad, and The Munchkin 2: Beating A Dead Horse

"The Good, the Bad, and the Munchkin 2: Beating a Dead Horse contains 56 new Wild West-themed cards specifically for use in The Good, the Bad, and the Munchkin, although they can also be added to any other Munchkin game.This expansion includes a new class, Cavalry, that allows you to sacrifice your treasure to gain a level when helping a non-Cavalry player. Since this level is gained as part of a combat, it can be the winning level."
 
This is not a stand alone game, requires a base game of munchkin to play (best with The Good, The Bad, and the Munchkin).