The First Newspaper April Fool (1774 or 1789)
There are two different stories that describe the first April Fool's Day hoax by a newspaper, but both stories claim it was a German paper.
The first story claims that in 1774 a German paper claimed it was possible to breed chickens of various colors by painting the area in which the mother hen lived. The hen would supposedly pass on the color of her surroundings to her offspring.
The second story claims that in 1789 a Berlin newspaper reported that hailstone the size of pigeon eggs had fallen on the streets of Potsdam, which caused hundreds of curiosity seekers to go to the town hoping to see this unusual weather phenomenon. Of course, no hailstones were seen.
Neither story has been confirmed.