?????

So there is this large advertisement outside my school on an advertisement board, with a bloody outline and "something is coming". For some reason (maybe Hungry Ghost Festival?), there are two yellow banners, with Chinese words on it, partially blocking the advertisement. So today after CCA, I was waiting for the bus and then suddenly, it seemed like a few objects hit the canvas as I heard a woosh sound and a few protrusions in the canvas which disappeared in a few seconds. This was followed by a weird screech.