I don't know what this thing is, but I walk by it all the time. I've always thought the cracks look like birds in flight.
Also, someone finally came and looked at my chimney. Huzzah! It was a simple caulk job, which I mostly suspected, but it doesn't do well to presume the easy fix is it when it comes to roofs. IMO. No idea what the cost will be, but I'm figuring it'll be on the lower end. Whew!