An invisible or barely-visible wall that materializes across a traveler's path at night. When it chooses to reveal itself, it appears as a massive, featureless white wall with stubby legs and small, bewildered eyes.

Blocks the road of night travelers. Pushing against it does nothing — the wall extends infinitely in all directions. Walking around it leads nowhere. Those who try to climb over fall back endlessly. It causes no harm beyond confusion and delay.