Please Do Not Feed the Weirdo (Goosebumps SlappyWorld #4)

While visiting a carnival, Robby and his sister Karla find themselves at a less-trafficked area. Inside a large penned-in area, they see a dejected-looking boy about their age sitting on the grass. A sign on the tall metal fence reads: "Please Do Not Feed the Weirdo." What will happen if they do?