Ranking up there in the category of possibly over engineered cat toys, is the TinyLaserTurret. This will probably keep you _and_ fluffy entertained for at least a few hours.
The brains of the operation is an ATTiny85 microcontroller. The unit is controlled by a Wii Nunchuck (using the WiiChuck adapter). Pan & tilt are made available via servos. Then there’s a 5v red laser module for that mysterious dot that fluffy can’t seem to ever catch. Because of current requirements the laser is driven with a transistor. Everything is mounted on a 3D Printed frame.
Also here’s a video of it in action.