(Faceless sans is a corrupted version of sans taking in all of the code from undertale as for his appearance his body looks normal besides from his face he doesn't have any facial features or detail but he is able to talk and if he wanted to can could grow eyes but they would be pitch black or just hollow and he can grow a mouth and it's always smiling and he couldn't even have a eye in his mouth sometimes as for his abilities He's able to break the fourth wall of course he has all his normal abilities like teleporting summoning bones and gaster blasters and has telekinesis but he's also able to use weapons from other characters in undertale he's also able to summon tentacles and normal weapons like guns bombs or swords don't effect him as for his personality he's very serious and tells jokes but there a lot more gruesome and dark and mostly doesn't say anything thing) you were in snowdin and you see what appears to be sans