Aufhockers are a deadly but straightforward menace which may grow up in the Schwarzvald. They are shape-shifters, creatures with elastic flesh that can assume any form. Though their overall mass always stays the same, they can compress themselves or inflate themselves to a great degree, giving them the ability to fit through almost any nook or cranny, and to assume the forms of men, animals, plants, and even inanimate objects.
They too have their rules, but these are much more straightforward than those of the Nachtmacher. The Aufhocker cannot move so long as it is being looked at. That is its sole weakness.
The Aufhocker is not particularly fast... This is not a Weeping Angel that will close with you from ten feet and kill you in the time it takes you to blink. If one were to blink very rapidly while looking at one, one would be able to see it move in a sort of slow motion.
Because of this, the Aufhocker prefers stealth, guile, and the advantage of surprise when attacking its victims, and its favored method is to creep up behind them, or as they sleep, and strangle them. Once choking, even if the victim somehow lays eyes on their killer, they will be no better off.
The Aufhockers do not drink blood, nor do they eat flesh, but rather they consume veins and the heart muscle. Victims of the Aufhocker will be found sliced open, with their arteries and veins meticulously stripped out and eaten.
Aufhockers can be injured by contact with silver, gold, and sacred oil. Pieces of them that are cut off from the main body while frozen will die, and dissipate into mud and salt. They also greatly dislike fish, and it is believed that they will leave alone someone whose diet consists largely of seafood because of the smell in the veins.
Aufhockers can be affected by symbolic eyes, but the length of time that the Aufhocker can be detained varies depending on the nature of the symbolic eye. Generally, the more realistic and three-dimensional the eye is, the longer the Aufhocker will be delayed.
A stylized eye scribbled on a door might freeze one for a few minutes. A fine painting, perhaps a full night. An ultra-realistic marble statue of a face with colored inlays to make the eyes look more realistic might be able to freeze one for a hundred years.
Animals can also halt Aufhockers, but because they have no scent and remain perfectly motionless, animals tend not to focus on them for too long after seeing them, unless they are specially trained.
Interestingly, (and perhaps this is related to their hatred of the creatures) fish, even dead ones, can freeze Aufhockers with their stare. Many people who know the creatures are about will nail fish to their walls. Reichland Aristocrats will often keep fish in glass bowls about their homes for added security.
Multiple identical eyes would do little to deter it, it would be effected a bit longer than if it were just one, but not much longer.
Multiple eyes only have a cumulative effect if they are of dramatically different styles and mediums. So a drawn eye, etched eye and a statue of a face would probably combine their periods, whereas three of one of them would give rapidly diminishing returns.
The Aufhocker isn't actually aware of the time it spends frozen. After the effects of the artificial eye wear off, it just becomes conscious again and can move. Eventually it would just become accustomed to each image in the loop, and be able to ignore them all.
A human's severed eye would have no effect. A fish's eye, even if it isn't in a zoetrope, will keep one frozen indefinitely until the eye rots away. Fish are special.