Companion Cube
Retinazer
Mannequin/womannequin in multiplayer won't update for anyone other than the host. If the host takes armor off an mannequin that they have armor updated onto, they can also take off a set, duplicating it. Vice versa is true, that they can overwrite other sets of armor by putting another set in its place, destroying it. You can recreate it by having a host put armor on a mannequin, have another player join, then have the host take the armor off, then have the joined player take the armor off. Or you can have the host put armor on an mannequin while a player is joined, then have the joined player try taking off the armor, even though nothing will appear. (Not entirely sure on last one, always been host)