Most Halloween props just sit there waiting for someone to walk past. This one does the opposite: it is an animatronic one-eyed pumpkin that spots a person, works out distance and angle, then opens its eye and follows them around the room. That is a lovely bit of stagecraft for a shelf display, and the tracking looks genuinely unsettling in the best way.
The maker started from a purchased 3D model and added an LD2450 mmwave sensor to it. The pumpkin itself is printed in PLA. Fitting the sensor inside was tight, but it needed only minimal adjustments to the design, and in fact only one part of the original model had to be changed at all. Keeping the electronics hidden inside the existing shell seems like a smart way to preserve the look of the piece.
Visually it is a strong prop. The body has a reddish-orange ribbed texture with a dark green curved stem, and the large blue mechanical eye pivots smoothly from side to side as it follows someone. A thin black power wire trails from the back of the pumpkin down the shelf pole, so it is not fully self-contained on the display, though that is barely noticeable in the scene.
There are a couple of open threads. Scaling the design up, as some have suggested for a front door setup, would apparently be much more work than the original build. On the file side, the maker found the membership cost worthwhile given the design effort involved, but hopes the designer will someday sell models without a subscription, and may reach out to offer the adjusted part back to them.