From GameWatcher: “If you’ve had any sort of continuous experience with Tripwire Interactive’s Killing Floor games, then you know that these guys have a particular penchant for holiday-related events. So we might get to butcher the Santa, his imps, and his reindeer on Christmas every once in a while, for example.”
Source: N4G PC Killing Floor 2's Halloween Event 2018 Might Dredge Something Up From The Black Lagoon