It’s a 3D printed skull attached to motors, lights and a stuffed body – in order to produce a Poltergeist sort of effect. When visitors to the haunted house draw near, the skeleton can be made to turn its head, revealing its grim visage and LED eyes.
This is the kind of Maker creativity that I love. The separate pieces mostly existed already, including the skull, the gears, Arduino for the electronics and more. It just took the need of some haunted house gear for those parts to end up together.
Wifibum also made this video of the poltergeist-style skeleton in action, and how the whole thing was put together:
(Personally, I will probably just be 3D printing a large-size pirate hook for the parties this weekend!)