It's hard to say for sure. Some of the stories could be based on real malfunctions. For instance, if an animatronic's wiring gets crossed, it could lead to strange movements and noises. However, when it comes to the really out - there horror aspects like the animatronics being possessed, that's probably just people's imaginations running wild. The creepy factor might be enhanced because Chuck E. Cheese is a place associated with kids, and any deviation from the normal happy - go - lucky atmosphere seems more menacing.
A lot of the horror stories are just that - stories. But there could be a kernel of truth in some. Maybe an animatronic did something unexpected due to a mechanical issue. But the idea that they are haunted or part of some kind of horror scenario is mostly made - up. People love to tell spooky tales, and Chuck E. Cheese animatronics provide a unique and somewhat unexpected backdrop for such stories.
Most of them are likely urban legends. These stories often get exaggerated over time. The animatronics are machines, and while they can malfunction and create spooky - looking situations, it's not likely that there's any real supernatural element to them.