Fred and George had also somehow managed to distribute their skiving snackboxs to the entire school, and students were suddenly vomiting abruptly, or bleeding profusely from their nose seemingly overnight - but only in Umbridge’s classes. The entirety of the Defence Against the Dark Arts NEWT class had started sprouting boils one Monday morning, all of them claiming that Umbridge’s classroom must be contaminated by something. Their real genius had been in subtly cursing Umbridge to start developing boils as well, and Umbridge’s classes had been cancelled for the rest of the day while Filch cleaned it top to bottom, all the while having a gas masked taped tightly to his head.