William Afton (Five Nights at Freddy's)

The Killer is an unseen villain in Five Nights at Freddy's, being a solely mentioned criminal who's horrible actions are revealed through posters in the game.

The Killer is a sadistic psychopath who dressed up as one of the mascots at Freddy Fazbear's Pizza. He used his kid-friendly disguise to lure five children into the back of the pizzarea where he supposedly murdered them and stuffed their remains into the mascots' costumes. While he was caught and arrested, the Killer indirectly caused an act of justice, as his actions got the dangerous restaurant shut down a few months after the events of the game.

Not because of the missing children, but because of the health issues of the mascots oozing out the children's blood and mucus from time to time.