Not quite pareidolia, but misperception: As I was driving this afternoon, I had stopped at an intersection before making a right turn. I looked to the left to see if any cars were approaching, and I saw an enormous bird, far bigger than an eagle, flying overhead. It was close to the car, and I glimpsed it for only an instant, against a cloudy gray sky.
Then it passed over the car and I could see it through the windshield to the right. On that side were trees near the street, and now I could see what the bird was: an ordinary crow. My first glimpse, without any reference points, made me think the bird was twenty feet or more over my head. When I got my bearings, I realized the crow had sailed over at no more than five feet or so above me.
Made me feel weird for just a few seconds, though.