If you feel like doing a mutator of a totally different kind, then try this zombie skins mod for version 1017.
Try this custom zombie skins mutator mod. I have changed the zombie skins textures for Killing Floor Steam version 1017 and incorporated them to KFChar.u file. This custom mod is good for version 1017. I am not sure if this will work for the updated versions, but if you have the updated version then make sure you keep a backup KFChar.u file in your System folder.
INSTRUCTIONS:
1. Unzip the KFSteam_MMutator file.
2. Copy/paste the two unzipped folders, "System" and "Textures" to your Killing Floor (Steam 1017) directory.
3. Rename your original KChar.u file from your "System" folder to KFChar_Original.u, and rename my KFChar_Temp.u file to KFChar.u.
4. Activate the KFMutator.
5. Play.
NOTE: Make sure your make a copy of your original KFChar.u file.
IMPORTANT: Please read this important message - click here.