You filthy, cheating 'what'?

Lee Jordan uses some colourful language during a Quidditch match

Extract from Harry Potter and the Prisoner of Azkaban

By J.K. Rowling

Harry was angry enough to hit Malfoy, but he couldn’t reach. Malfoy was panting with the effort of holding onto the Firebolt, but his eyes were sparkling maliciously. He had achieved what he’d wanted – the Snitch had disappeared again.

‘Penalty! Penalty to Gryffindor! I’ve never seen such tactics!’ Madam Hooch screeched, shooting up to where Malfoy was sliding back onto his Nimbus Two Thousand and One.

‘YOU CHEATING SCUM!’ Lee Jordan was howling into the megaphone, dancing out of Professor McGonagall’s reach. ‘YOU FILTHY, CHEATING B–’

Professor McGonagall didn’t even bother to tell him off. She was actually shaking her fist in Malfoy’s direction; her hat had fallen off, and she, too, was shouting furiously.

Harry Potter and the Order of the Phoenix

By J.K. Rowling