I know this is old by now, but I dont read Gen Discussion often. I almost stuff myself earlier Baddy :(
Im building a halloween house on Destruct and I look over and theres a random renderman face and I jumped. Best halloween gift ever <333!
EDIT:
YES, a Renderman face pops up in dark maps (You can stand in light and he will still appear, as long as it is a dark map. Examples are Kitchen Dark, Bedroom Dark, Destruct (My Favorite), Halloween Slate, etc etc etc). THIS IS FACT! It is an easter egg for Halloween.
NO, Renderman did not exist pre-update - Those were all lies
NO, Renderman does NOT "crash your game" as some fat morons are claiming
NO, Renderman is not a physical player, its just a particle
YES, you are safe on your server, you are not being "watched" like some fat morons are saying
YES, you do need to have the pumpkin mod enabled in order to see him
Type BSD_check(); into console to see him manually (Must be server host)