The players only knew the dreaded Dry Gulch Gang were terrorizing the citizens of Lesterville. Even the sheriff was scared to venture from his office, but offered a considerable reward for bringing the infamous outlaws to Justice.
With that in mind, the 6 players deployed their own gangs in search of the Dry Gulch crew. All seemed normal until the outlaws in questions showed up. They were decidedly disheveled even for them, and walked with an awkward gate. Things got really weird when the first Dry Gulcher attacked a citizen, biting them!
We used the regular FfoL rules with a twist. When a black suit face card was played, players could move a zombie 8 inches however they wanted. One a red face, a group. A group consisted of any zombies an inch or closer together. The zombies only used an 8 sided dice, but the same zombie or group could be moved by multiple times, so swarms were a danger. Then, at the end of the turn, after all the players had moved, all the zombies were moved towards the closest non-zombie.
At first, the players used the zombies to attack each other or create more zombies. This tactic, however soon had most the citizens running around as drooling, blood crazed monsters. Soon, the players were just trying to survive.
Only a "kill" result would bring them down. Wounds and pins were ignored.
But, eventually the Dry Gulch gang was picked off, one by one. El Guappo and Johnny One-Leg were able to claim the reward.