They haven't been made to disappear, unfortunately. Retroactively dealing with the effects of bugs would lead to a huge amount of code in the game dedicated to just cleaning up things from previous versions. What you can do to clear them out is cause them to have a script error. This can be done by going into single player and entering the following command while hovering your mouse over the NPC: Code: /entityeval self.behavior = "thisisastring" This will cause the NPC to die. Any duplicates will not respawn, but the originals will respawn after a few seconds.