Not a mod, but I know there's some characters in-game who are stripped of this or that appearance during the day, and then change during the night again, just like the return of any other power. Only currently in-game example that my sleepy mind can come up with on the spot is Rapunzel, whose hair gets longer at night, but I know there's been others too- I think Kurt from X-Men would turn blue at night?

So basically look pretty human during the day, less so at night?