From BookJive

Neville Longbottom is a Gryffindor student in Harry's year throughout the series. Neville Longbottom was born in the end of July, one day before Harry Potter, to Frank and Alice Longbottom, Aurors and prominent members of the Order of the Phoenix during the time of Lord Voldemort's original reign. The Longbottoms are one of the last few old pure-blooded families. Neville's closest friends are Harry Potter, Ron Weasley, Hermione Granger, Ginny Weasley, and Luna Lovegood. Neville is portrayed as socially awkward in the greater Hogwarts community, but he is extraordinarily gifted in Herbology. After joining Dumbledore's Army, and practicing defensive curse-blocking with Harry's help in the special DADA classes which Harry taught, Neville begins to gain confidence in himself and his magical abilities.

Both of Neville's parents were tortured by Death Eaters, notably Barty Crouch Jr, Bellatrix Lestrange, Rodolphus Lestrange and Rodolphus' brother, Rabastan Lestrange, with the Cruciatus Curse, which may explain why he was so affected by the use of such a curse on a spider in the Goblet Of Fire. They are now in a closed ward of St Mungo's Hospital for Magical Maladies and Injuries. Neville's paternal grandmother Augusta has raised him from a young age.

Neville is terrified of his grandmother, who is a strict disciplinarian and a perfectionist. She appears to want Neville to follow in his father's footsteps, regardless of his desires or suitability. When Neville tells Professor McGonagall that his grandmother feels Charms is the "soft option" over Transfiguration, McGonagall informs him that "It's high time your grandmother learned to be proud of the grandson she's got, rather than the one she thinks she ought to have."

Neville is probably related to the Black family: Callidora Black, a granddaughter of Phineas Nigellus Black, married a Longbottom. Many fans suspect her to be Neville's great-grandmother.

The loss of his parents to madness has affected Neville greatly, and he has kept their condition a secret. Harry, however, is told of their fate by Albus Dumbledore, and Ron Weasley, Hermione Granger and Ginny Weasley, discover the truth accidentally in St Mungo's in the Order of the Phoenix.

Neville also has an uncle, Algie (surname unknown), who seems to have participated in his upbringing to some extent. He gave Neville Trevor, a pet toad, on his acceptance to Hogwarts. When Neville was a child, Algie attempted to 'scare the magic out' of Neville, throwing him off the Blackpool pier to see if he would float (or at least not be harmed), and dangling him out of a window — before accidentally dropping him (Neville's magic caused him to bounce).

In addition to Trevor the toad, Neville also has something of a pet in his Mimbulus mimbletonia, an extremely rare plant resembling a gray cactus covered in boils, which was a birthday present that his great-uncle Algie got for him in Assyria.

Neville's lack of self-confidence affects his abilities as a wizard-in-training; despite being pure-blooded, in his early years at Hogwarts Neville shows an ineptitude with magic and a lack of focus that often gets him into trouble. However, he also shows courage, strength and potential, earning ten house points and securing Gryffindor the House Cup at the end ofIn Harry Potter and the Sorcerer's Stone.

In Harry Potter and the Order of the Phoenix, Neville's magical abilities improve dramatically under Harry's special Defence Against the Dark Arts training in Dumbledore's Army. He also receives far greater characterization than he has in the past, with Harry (and thus the reader) coming to understand him on a deeper level, beginning when Harry's friends learn about the fate of Neville's parents at St Mungo's Hospital. Shortly afterwards, a number of Death Eaters escape Azkaban, including Bellatrix Lestrange, the witch who was mainly responsible for torturing his parents. Neville then devotes himself, with surprising fervor, to Harry's training regimen, and becomes second only to Hermione in terms of aptitude. To Neville, as with Harry, the fight against Voldemort is personal.

Neville saves Harry's life during the battle in the Department of Mysteries, and plays a key role (if inadvertently) in keeping Lord Voldemort from knowing the prophecy made about "Dark Lord and Harry Potter". He and Harry are also the only students left standing after the battle, despite a Death Eater breaking both Neville's nose and his father's wand.

Because the prophecy was "released" during the battle, neither Harry nor Neville manages to hear its contents. Albus Dumbledore, to whom the prophecy was originally made (the version in the Department of Mysteries being a copy), explains that it concerns "the Chosen One," a wizard that would have the power to fight against Voldemort. This Chosen One would be born "as the seventh month dies," and thus could refer to either Neville (born July 30, 1980) or Harry (born July 31, one day later). It is Dumbledore's opinion that Voldemort indeed chose his "Chosen One" by attacking Harry rather than Neville.

It is unknown whether Neville himself knows just how close he came to being The Boy Who Lived.

In Harry Potter and the Half-Blood Prince, Neville has received a new wand, after his former one was broken during the battle at the Department of Mysteries; a wand made of cherry wood and unicorn hair, which was apparently one of the last ones Mr. Ollivander sold before he disappeared. The wand appears to have added further improvement to Neville's school performance (it has been commented on several occasions that 'the wand chooses the wizard', and that one 'never gets as good results with another wizard's wand': Neville had previously been using his father's wand). Neville is invited to Horace Slughorn's party on the train, along with Harry and Ginny.

It is revealed that Neville achieved an "Outstanding" in Herbology, and he did well in Defence Against the Dark Arts and Charms, earning an "Exceeds Expectations". He got an "Acceptable" in Transfiguration, and is disappointed when Professor McGonagall will not allow him to join her N.E.W.T.-level class. Instead, he continues to advanced Charms.

Neville wants the DA (Dumbledore's Army) meetings to continue, as he feels it has helped him and the others to improve their skills. During the Battle of Hogwarts, Neville answers the call for help, and he fights against the Death Eaters once again. He does not appear to be as important there as he was in the Department of Mysteries Battle (Harry sees him on the ground clutching his stomach), but he may have been the person who stunned Fenrir Greyback (he was the only Defender that was not locked in battle with another attacker at the time).

Trevor

Trevor is Neville's favourite pet and his only toad. He was given to Neville by his Uncle Algie upon Neville's gaining admission to Hogwarts. Neville loses him on a regular basis. For example, Trevor is lost on the train while on their journey to Hogwarts in their first year. Hermione Granger helps Neville search for the toad. This search is the setting for the first meeting between Harry Potter and Ron Weasley, who were sitting together in a compartment at that time, and Hermione. The toad is later found by Hagrid after the boat trip for the first-years to get to Hogwarts.

It may be assumed that Neville takes Trevor with him to class as he is often mentioned as being used by the Professors in class. Professor Flitwick has made Trevor zoom around in Charms classes. Additionally, in an effort to bully Neville, Professor Snape used Trevor to test Neville's Shrinking Solution.

In Harry Potter and the Philosopher's Stone, Hagrid mentions to Harry in Diagon Alley, before he goes to Hogwarts, that toads are rather an out of date fad. Therefore, Neville's ownership of this creature confirms his status as the token outsider of Harry's year.