Cedric Diggory

Cedric first faces Harry Potter during the Quidditch tournament in Prisoner of Azkaban, and ends up catching the Golden Snitch after Harry faints in the presence of Dementors. Cedric offers to replay the match but the offer is declined by Gryffindor captain Oliver Wood, who feels that Diggory had won the game.

The next year, Cedric and his father, Amos, attend the Quidditch World Cup alongside Harry, Hermione Granger and the Weasley family. Upon arriving at Hogwarts for his sixth year, Cedric puts his name forth in the Goblet of Fire and is selected as the Hogwarts champion alongside Fleur Delacour from Beauxbatons and Victor Krum from Durmstrang. Despite all three champions being chosen, the Goblet of Fire nominates Harry to become the fourth Triwizard Champion. Cedric remains kind to Harry whilst everyone else assumes Harry was lying when he states that he did not put his name in the Goblet of Fire.

Despite having two champions from the school, the majority of Hogwarts students support Cedric, with students even creating enchanted badges that say "Support Cedric Diggory, the Real Hogwarts Champion". Cedric is opposed to the badges and tries to get his classmates not to wear them. In the first task, Harry gives Cedric a hand by informing him in advance that the task involves dragons. Cedric's dragon is a Swedish Short-Snout, from which he has to retrieve the Golden Egg it is guarding. Cedric achieves this by transfiguring a rock into a labrador to distract the dragon whilst he retrieves the egg. The dragon is distracted by Cedric, but burns half of his face. After completing the task, Cedric is informed by Barty Crouch, Jr. to place the egg underwater and listen to it. Cedric takes the egg to the Prefect's bathroom and figures out that the second task will involve the merpeople.

At the Yule Ball, Cedric attends with Ravenclaw's Seeker, Cho Chang, as his date. Towards the end of the night, Cedric informs Harry about placing the egg underwater as repayment for Harry warning him about the First Task. Knowing he will have to breathe underwater for one hour during the Second Task, Cedric applies the Bubble-Head Charm and retrieved Cho, his hostage, from the Black Lake. He quickly warns Harry about the time limit before finishing, as Harry is worried about Fleur's hostage as she has been eliminated. After both tasks were completed, Cedric and Harry are tied for first place in the Tournament standings.

Cedric's father travels to Hogwarts to be with his son for the third and final task in the tournament. Amos is displeased with Harry due to the media storm that has been covering him during the tournament, for which Cedric apologises for and defends Harry. Due to being tied at first place, Cedric and Harry enter the maze together, but eventually split up. After escaping a Blast-Ended Skrewt, Cedric is attacked by a bewitched Viktor Krum, who tries to use the Cruciatus Curse on Cedric per the direction of Crouch Jr., before being rescued by Harry before splitting up again. Cedric spots the Triwizard Cup and races towards it before being attacked by an acromantula. Harry and Cedric reunite again and defeated the Acromantula together, finding themselves at the Triwizard Cup. Cedric urges Harry to take the Cup as a favour for saving his life twice that evening; after realising that they've both helped each other, they agree to both take the Cup. The Cup turns out to have been enchanted by Crouch Jr. to act as a Portkey, which takes them to a graveyard in Little Hangleton.

Upon their arrival in the graveyard, Cedric draws his wand, suspicious about their surroundings. Moments later, Peter Pettigrew emerges carrying a small being, which turns out to be Lord Voldemort. While Harry is suffering through searing pain through his scar due to the Horcrux in his body responding to Voldemort's presence, Voldemort orders Pettigrew to "kill the spare", prompting Pettigrew to use the Killing Curse on Cedric. During Harry's subsequent duel with Voldemort, their wands connect, and Cedric's ghost emerges from the wand along with the ghosts of Harry's parents. Before distracting Voldemort, Cedric asked Harry to take his body back to his parents. Harry broke the connection and sprinted towards Cedric's body, summoning the Cup to transport him and the body back to Hogwarts.

Due to Cedric's death, the Leaving Feast on the last day of the school year is instead turned into a memorial service for him. Dumbledore informs the students, against the wishes of the Ministry of Magic, that Cedric was murdered by Voldemort. In the following months, the Ministry of Magic, under the direction of Cornelius Fudge, orchestrate a smear campaign on Harry and Dumbledore in an attempt to silence panic at Voldemort's return and hush up Cedric's death. Cedric's death proves to be an inspiration for the students of Hogwarts, and eventually rebellion against the iron fist Dolores Umbridge imposes onto the school. This leads Harry, Ron and Hermione to form Dumbledore's Army for the students of Hogwarts, considering Umbridge is refusing to allow students to learn Defense Against the Dark Arts. Harry believes that students need to know how to defend themselves, due in large part to the return of Voldemort and the re-forming of the Death Eaters, so that no other student meets the same fate as Cedric. Harry continues to honour Cedric's memory through Dumbledore's Army and by keeping one of the "Support Cedric Diggory" badges.