Well, this isn't in-game - but during design work for the game - When attempting to add details to the texture of this youth civilian model I accidentally used the wrong settings for mapping the fingers and fingernails, and as a result ended up making the model look like it has tattoos on the skin.
I've found in my experience that some of the funniest pics come from design work for a project - not in-game screen shots, especially when things don't work as planned or have bugs.
For those who haven't been here too long: This model is actually already in the repo and game folders, it just wasn't actively used in-game because I didn't finish working on it, something I'm now returning to.