Neville Longbottom
Background
Neville Longbottom is a wizard from house Gryffindor and student at Hogwarts School of Witchcraft and Wizardry. His familiar is Trevor.
During the events of Harry Potter and the Sorcerer's Stone (2001) played by Matthew Lewis
The students arrive at the station and take boats to Hogwarts. Professor McGonagall tells the first year students that they must go through the process of being sorted into their respective houses and she explains the points system and the house that wins the most points will win the house cup. Neville finds Trevor and Draco Malfoy makes a comment about Harry Potter, which causes the other students to exclaim. The first year students are brought into the Great Hall and brought to The Sorting Hat. Albus Dumbledore tells the first year students the rules including that the Dark Forest is off limits. During dinner, Seamus Finnegan tells Dean Thomas and Neville that he is of mixed heritage. Nearly Headless Nick introduces himself to the new students and The Grey Lady, The Bloody Baron, and Fat Friar float around the students. Percy Weasley gives the password to the Fat Lady and Percy takes the first year students into the Gryfffindor common room. Mail comes and Dean tells everyone Neville got a Remembrall. Later, Madame Hooch teaches the students how to ride their broomsticks. Neville loses control of his broomstick and eventually falls and breaks his wrist. While Madame Hooch is taking Neville to the hospital, Draco steal Neville's Remembrall, but Harry gets it back. At Halloween dinner, Neville tells Harry that Hermione Granger was crying in the bathroom. As Harry, Ron and Hermione are trying to sneak out of the common room, Neville stops them and Hermione uses a freeze spell on him. During the end of semester dinner, Gryffindor wins the house cup due to the actions of Harry, Hermione, Ron, and Neville.
During the events of Harry Potter and the Chamber of Secrets (2002) played by Matthew Lewis
Professor Sprout walks into class and tells the students they are going to be re-potting Mandrakes. She warns them that the Mandrake seedlings can cause those who hear their cry to faint and tells the class to put on their ear muffs. Neville falls down and Professor Sprout thinks he neglected his earmuffs, but Seamus tells her, Neville just fainted. In class, Gilderoy Lockhart introduces himself to the students as their new Defense Against the Dark Arts teacher. He un-cages Cornish Pixies in class and they start to unleash havoc onto the class. He runs away after asking Hermione, Harry and Ron to capture the Pixies when the Pixies steal his wand. Hermione casts an Immobulus spell which causes Pixies to slowly float in the air. Neville, who was flown and stuck onto a chandelier by the Pixies, asks why it always has to be him. Later, Neville runs up to Harry and then takes him back to Harry's room, which has been torn apart and his things strewn on the ground and Harry realizes the journal is missing. Before the end of the year feast, Dumbledore asks for a round of applause for Professor Sprout and Madam Pomfrey and all of the students and professors clap, including Madam Pince. Hagrid returns and everyone gives Hagrid a round of applause.