Zombie (human AI)

A zombie (not to be confused with a conventional zombie) is someone who walks around aimlessly and without task, despite being in a context and interactive environment, for example, a store or a market. These people don't appear to acknowledge their environment or their surroundings.

Classically, like actual zombies, zombies are likely to also be walking slow and erratic, often with stop/start behaviour.

Behaviour
Zombies are notoriously difficult to navigate because they are seemingly oblivious to other people and proceed in random walking patterns. They will often engage loitering behaviour and obstruct passageways and can be difficult to get past without engaging 'wake up' behaviour (EG tapping them on the shoulder or loudly addressing them).

They are especially difficult in large numbers, and whilst navigating with large objects (such as a trolley or a car). Zombies seem to invoke the law of pedestrians as they can often impede cars and other vehicles.

The confusing nature about zombies is, despite the fact they are humans who have opted to go to a store or other interactive place (which implies there is something specific they need to get), zombies will generally not look at or interact with their environment, and will appear to be looking at nothing in particular. Why this occurs in human nature isn't entirely clear, but it's suspected to be a form of daydreaming.

Related
See also:

Walking bulldozer (human AI).

Rolling blockade (human AI).