Reminds me of an old railway dispatcher game where trains were abducted by aliens & cursed by witches... This one ^
...looks more like a misplaced part of a 3D asset. By the way, there is also a UFO at Cajon Pass, which is part of a film set!
At first I thought it was supposed to be an insect or a bird. But then I remembered that there are neither birds nor insects in the game. I've yet to play Cajon Pass. Maybe that'll be my next go-to after I redo Peninsula, now that there's a mod out that restores the timetable for the Bombardier Cab Car on the Baby Bullet trainset.