- "Harry's got himself a rogue Bludger!"
The house-elf Dobby tampered with a Bludger during the 1992–1993 school year. Its purpose was to injure Harry Potter, with the hope that he would be sent home from Hogwarts; the serpent of Slytherin inside the Chamber of Secrets was active and petrifying students at the time. The Bludger caused the Gryffindor Beaters Fred and George Weasley to protect Harry and not watch out for the rest of the team, until Harry insisted they leave him to deal with the bludger himself. The Bludger succeeded in breaking Harry's arm, but Harry also succeeded in catching the Golden Snitch, thus winning the Gryffindor vs Slytherin Quidditch match resulting on him letting go of his Nimbus 2000 and falling on the sandy ground in the middle area due to his broken arm.
After the game was over, Fred and George struggled to stuff the Bludger back into its crate, as it was still putting up a 'terrific fight.' Gilderoy Lockhart later attempted to fix Harry's broken arm but instead made his bone disappear. Dobby later revealed to Harry in the hospital wing that he was the one who tampered with the Bludger, and apologised for setting it on Harry, which contradicted Harry's earlier theory of Draco Malfoy being the culprit.
Behind the scenes
In the film adaptation of Harry Potter and the Chamber of Secrets, the Gryffindor Keeper Oliver Wood's broomstick is broken off on the shaft by a rogue Bludger only as he and Harry tell each other the warnings. Shocked and a little concerned about a serious reason, Hermione Granger gets Ron Weasley, Rubeus Hagrid, and the rest of the crowd to leave their seats right to the middle of the stadium where Harry has fallen and she destroys the Bludger by using the spell called Finite Incantatem right after the game, when the Bludger continues its assault on him on the ground.