Nigel
Background
Nigel Wolpert is a wizard from house Gryffindor and student at Hogwarts School of Witchcraft and Wizardry.
During the events of Harry Potter and the Goblet of Fire (2005) played by William Melling
At Hogwarts, Neville Longbottom and the other students stare in awe as Hagrid directs a carriage being pulled by seven pegasus as it lands on the school grounds. The students, including Nigel, then watch as a large ship rises out of the water. Later, Nigel drops off a package to Ron Weasley, which turns out to be a hideous dress robe for the upcoming Yule Ball. He tries to get an autograph from Harry Potter, but Ron tells him later.
During the events of Harry Potter and the Order of the Phoenix (2007) played by William Melling
During the Hogwarts banquet, Albus Dumbledore welcomes back Professor Grubbly-Plank as the Care of Magical Creatures while Hagrid is away. He then introduces Dolores Umbridge as the new Defense Against the Dark Arts teacher. Dolores interrupts Dumbledore and tells the students that the Ministry of Magic is very concerned about their education. Hermione Granger organizes a meeting with some of the other students at Hog's Head, where Barman works. Somewhat Doubtful Boy wonders why they need to be taught how to combat the dark arts and Slightly Creepy Boy asks Harry to describe more of what happened when Cedric was killed. Nigel asks if Voldemort is really back, and Harry tells everyone he is. They then form a group called Dumbledore's Army. Dumbledore's Army, which consists of Harry, Hermione, Ron, Fred Weasley, George Weasley, Ginny Weasley, Neville, Cho Chang, Nigel, Dean Thomas, Padma Patil, Parvati Patil, Somewhat Doubtful Boy, Slightly Creepy Boy and others, uses the Room of Requirement to train. More students join Dumbledore's Army. During one of their training sessions, they are caught by Dolores, Mr Filch and the student members of the inquisitors. Dolores replaces Dumbledore as head of Hogwarts and all members of Dumbledore's Army are required to go to detention where they are forced to experience the same abuse as Harry was.
During the events of Harry Potter and the Half-Blood Prince (2009) played by William Melling
Dumbledore introduces the students to Professor Horace Slughorn and tells the students that dark forces are trying to penetrate Hogwarts.